Next man up is a series of articles examining players further down the depth chart, particularly young players being developed for larger roles.

This time, we are looking at cornerback Quandre Diggs.

Draft Flashback

Once the concussion to Rashean Mathis from Week 7 against the Vikings was diagnosed to be the root of a mysterious illness in London, it didn't take long for him to go on season-ending IR. Assignments for everyone below Slaytumbo in the depth chart shuffled considerably with the loss of Mathis, but that wasn't the end of Detroit's injury problems at cornerback. Josh Wilson went down with a season-ending knee injury against Green Bay on the road in Week 10. That same game, Nevin Lawson left the game with a possible concussion.

All of these injuries to cornerbacks put tremendous pressure on Quandre Diggs to step up since fellow rookie Alex Carter was already on IR due to a preseason injury. And step up he did: Quandre the Giant delivered week after week, dominating PFF grades on the way to a lengthy highlight reel ably presented by our own Christopher Tomke.

It is hard to believe such a rookie season could be turned in by a sixth-round pick, but even early reports from July 2015 had Diggs as the favorite to take over the nickel spot. By the end of the year the POD faithful certainly believed, voting Diggs its Rookie of the Year. This week we turn back the clock to examine the things that may have kept Diggs on the board for the Lions to select late in the draft.

NFL.com Draft Profile:

Intelligent player with plus instincts. Anticipates routes well and attacks the throw. Has feet to mirror and chase crossing routes.

Can be mismatched by tall receivers no matter where he plays on the field. Could struggle against short-area speedsters from slot. Has major issues getting off of blocks.

CBS Sports:

Tracks the ball well over his shoulder with natural ballskills...instinctive nose for the ball, putting himself in position to make plays...highly competitive and tough, both physically and mentally...played both inside and outside, playing primarily in the nickel as a senior

lack of core power and length leads to him falling off bodies, struggling to finish tackles...inconsistent pursuit skills and unreliable as an open-field tackler...receivers can block him out of the play without much fuss.

SB Nation.com's Ian Boyd:

When this player can be trusted to make tackles against the run, play great man coverage, and blitz the edge he's arguably the best option college teams can find for filling the nickel role.

Examples include LSU's Honey Badger, Florida State's Lamarcus Joyner, and Texas' Quandre Diggs.

The less than ideal height and weight were the first things brought up in any pre-draft analysis of Diggs, but there are a few other notable factors we can investigate on tape. His coverage skills are praised a lot, but the questions start when an opposing player manages to get the ball in his hands. In a few cases, Diggs' tackling was doubted. Somewhat related to both the size critique and the tackling issue was whether Diggs could get off perimeter blocks and make plays on ball-carriers in space.

What we'll examine from 2015 film are how Diggs' tackling and cover skills stacked up against what was reported before the draft and if his height really was an issue. As the first item on the list, today let's dispense with the ridiculous notion that Diggs' tackling and run support can't be trusted.

Working with teammates and sidelines

As stupidly basic as it sounds, defenders are supposed to position themselves to be in the way of ball-carriers and either redirect them to where the defender wants him to go or make the tackle. Depending on the run fits and specific assignments, defenders may be instructed to force the runner horizontal and "spill" them to the outside or "contain" by holding the edge and forcing the runner back inside. As the spill and contain jaws of the run defense clamp shut on the runner, someone eventually makes the tackle (or everyone gang-tackles, which is even better).

2015 at SEA, 3Q (0:28). First-and-10 at the Seattle 47.

From an initial double slot shotgun formation, 3 QB Russell Wilson motions 88 TE Jimmy Graham from the far left wideout spot to reset in-line as a blocking TE outside the left tackle. This shifts the Detroit defense inward (particularly 57 LB Josh Bynes) and reveals to Wilson he is facing man coverage underneath. This coverage (2 Man, since both safeties are high) plus the way the defense is arrayed on the field is nice for Seattle because they have an alert bubble screen to the right they can activate.

89 WR Doug Baldwin (with his hand up in the screenshot above) has outside leverage on 28 CB Quandre Diggs, who is creeping up near the edge of the box in a good run support/anti-quick slant position. At the top of the screen, 23 CB Darius Slay is backed off quite far from 15 WR Jermaine Kearse. This is a setup that favors the bubble screen because Kearse has space to set up the block on Slay and Baldwin will be running away from Diggs before the ball is thrown.

The initial step by Diggs to the inside is what makes me think he was trying to take away the quick slant, but he recovers fast. Baldwin catches the ball right around the part of his route marked on the picture as point A. Both Slay and Diggs react to Wilson's early throw by reversing direction, moving up to play the screen. As expected, Kearse floats up to the 49-yard line and sets up to block; he is completely prepared for Slay and walls him off to the outside.

Now take a look at the path Diggs follows. He hops inside against a slant and then reverses direction to follow Wilson's eyes and throwing motion. Around the spot marked point C on the picture, Diggs has already turned his head and locates Baldwin. At that point, he knows what he's dealing with and flattens his pursuit angle to move perpendicular to the sideline and spill Baldwin to his "outside help" (nominally Slay, but in this case it's really the sideline).

You can tell Diggs knows what he's doing here: a slight hitch up as he passes the golden "50" on the field takes away the inside cutback lane to force Baldwin outside. There is nowhere to go since Baldwin is boxed in by the back of his own blocker to the front, the sideline to his right, and an active defender to his left. Diggs pounces and finishes the play with an ankle tackle, holding Seattle's gain from an advantageous pre-snap position to four yards.

2015 at STL, 2Q (14:55). Second-and-10 at the Detroit 37.

From an interesting 11 personnel Weak I-formation, the Rams run outside zone right with 89 TE Jared Cook lined up at the fullback position. 27 HB Tre Mason is supposed to flow right behind the offensive line with Cook going against the grain to kick out the back side force/contain player. The base play is dressed up with a fake jet sweep by slot receiver 83 WR Brian Quick (lined up in front of Diggs).

At the snap, Diggs follows his man across the formation (it was Cover-1 man-to-man coverage behind the front). When Mason gets the handoff, he runs into a penetrating 92 DT Haloti Ngata at the spot marked point A in the picture and has to hit the brakes to avoid getting blown up for a loss. After reversing field, he finds that our end man on the line of scrimmage 98 DE Devin Taylor has over-pursued to the inside. Instead of getting kicked out, Taylor leaves no crease but the back door is wide open.

Mason breaks it wide (point B in the picture), and the only guy remaining on that side of the formation is 23 CB Darius Slay as secondary contain. Although 18 WR Kenny Britt only barely gets tangled up with Slay, it is enough to allow Mason to bounce outside of Slay at point C in the picture. Remember Brian Quick was coming around on that fake jet sweep action? He realizes Mason is coming into his path and tries to turn into a lead blocker at the last minute.

Look who makes the stop here and where on the field this occurs: about the time Mason is passing through point B, Diggs sees what is happening and switches from man coverage mode to run support mode. He widens and assumes the role of tertiary contain to back Slay up. After dodging Quick's feeble block attempt, Diggs stops Mason's progress until help arrives.

Without this heads up play by Diggs, Mason probably breaks it for a long run before being pushed out of bounds by IAQ. Instead, the Rams are limited to 5 yards instead of moving the chains. Ziggy sacked 17 QB Case Keenum on the next play to force a punt.

You can see how at the end of the play Diggs has become a force defender and sets the edge to funnel Mason back to his inside help; just check the angle he has in the still screenshot I took with the sideline identified. If you watched this on the broadcast, chances are (like me) you probably did not notice this great run support play by Diggs. It happened largely away from the ball at the edge of the screen and was not pointed out by the TV broadcast team.

Solid play recognition

2015 OAK, 2Q (3:38). Second-and-15 from the Detroit 44.

This is a slightly delayed jailbreak screen to 15 WR Michael Crabtree. Diggs is over the slot receiver, 10 WR Seth Roberts. In the offensive design, Roberts floats in front of Diggs and then breaks for Slay, letting 72 LT Donald Penn come up behind Roberts to block Diggs and open a lane. In addition to Penn, 61 C Rodney Hudson also releases at the snap and keeps and eye on sealing 94 Ezekiel Ansah to the inside. This clears the way for Crabtree to turn upfield near the hash.

The defense plays it safe since the Raiders are behind schedule in second-and-long. Austin's call is Cover-2, so zone pass defenders in the back seven are watching the quarterback and keying off his eyes and ball handling. The instant 4 QB Derek Carr telegraphs the screen, Diggs reads it and breaks. You can see here that the ball has barely left Carr's hand but Diggs is already focused on getting to Crabtree. So quick is Diggs' read that he is able to attack up the field before Penn can get in position to block.

This is solid recognition by Diggs, who decisively takes it to the offense. This stop on Crabtree held the Raiders to a 2-yard gain and set up a nice third-and-long for the Lions' defense.

2015 DEN, 4Q (3:37). First-and-10 at the Denver 49.

When Denver's offense came to the line, Diggs started hollering something to 55 MLB Stephen Tulloch. Pointing out something repeatedly and getting Tulloch's attention twice before 18 QB Peyton Manning could set to snap the ball, Diggs clearly saw something to tip the play.

I can't conclusively say what was going on, but I believe Diggs was looking at his assigned receiver, 11 WR Jordan Norwood. From the All-22 box angle (shown here as an inset), it looks like Norwood's lead foot is turned. This is not a natural alignment if a receiver is going to try and get off the line to run a route, but it is a good way to stand if you intend to push off on a crackback block. Tulloch ends up moving over in anticipation of an outside run, and in fact the Broncos run crack toss to the left with Norwood as the crack blocker.

On the bunch side of the formation, 11 WR Norwood cracks down on 98 DE Devin Taylor, 10 WR Emmanuel Sanders loops to seal Tulloch to the inside, and 81 TE Owen Daniels is the lead puller to block the edge (31 CB Rashean Mathis). The reason nobody picks up Diggs is that 92 DT Haloti Ngata gets an excellent shove on 61 C Matt Paradis, stalling him just a bit after the snap.

Diggs takes a decent angle to 22 HB CJ Anderson and gets just enough to trip Anderson up as he tries to turn the corner. Although the Broncos had numbers to the play side (can count them in the diagrammed screenshot: six blockers for five defenders since Ngata is to Paradis' right), the Lions outflank the play thanks to a great pre-snap read (whatever it was that he saw) and aggressive run support from Quandre Diggs.

Next time: Judge me by my size, do you?

Quandre the Giant delivers on run support and open field tackling, but some may worry about the amount of ankle tackles over full wrap tackles. This is by design and should not bother anyone. Remember, Quandre Diggs is built lower to the ground: it doesn't make any sense for a 5'9" guy to try and tackle a 6'1" guy like Michael Crabtree high. And since he'll normally be run support on the outside rather than in a funnel alley, there won't be as many opportunities for squared up hits.

This is simply a fact of life for smaller defensive players. Consider this writeup on Chris Borland's tackling technique from Niners Nation:

Frequently, though, he makes tackles by diving for the ankles. Generally this is effective. It usually resembles a single-leg takedown in wrestling and allows Borland to either bring the runner down or prop him up so that other defenders can attack the ball. It also mitigates some of the issues that his size presents: taking down larger defenders is easier the lower to the ground you can get.

If Diggs were a bigger player, his tackling technique would look different but what he does now just works. The bottom line is that he gets the guy with the ball on the ground.

This is not to say that a height disadvantage can always be mitigated by smart play and good technique. If we're going to be realistic about how Diggs can be used in various match-ups, size absolutely needs to at least be taken into account. Next time we'll look at some plays that demonstrate why it cannot be ignored.