Topics this week include a look at what could have been if the Chargers had traded their franchise quarterback for a rookie, a comparison of the way two very different teams have drafted and more.

What could have been for Rivers and Mariota

Philip Rivers truly wanted to finish his career as a Charger -- a San Diego Charger -- but when he crosses paths with Marcus Mariota at Qualcomm Stadium on Sunday against the Tennessee Titans, it'll allow for one of the more recent intriguing "What if?" games to be played.

What if the Chargers and Titans had pushed to complete a trade in which Rivers went to Tennessee and Mariota would have been the No. 2 overall pick by San Diego in the 2015 NFL draft?

Rivers and wife Tiffany would have welcomed their eighth child last October in Nashville, less than 90 miles from where they met as seventh-grade sweethearts in the deep south of Athens, Alabama.

Mariota, not Rivers, would have been appearing at public rallies to get a "yes" vote on Tuesday's stadium initiative to salvage the team's future in California's deep south, San Diego.

Rivers' extended family would be making short drives to Nashville to see him play and visit the children. Mariota's family, anchored in Hawaii, would have merely traveled across the Pacific Ocean to enjoy his NFL career.

Dan Fouts would still hold the Chargers' all-time passing record, and Chargers offensive coordinator Ken Whisenhunt might still be the Titans head coach.

Ken Whisenhunt returned to San Diego in January after a brief stint in Tennessee, where he served as the head coach for the first eight games of Marcus Mariota's rookie campaign. Gregory Bull/AP Photo

Rivers can only live with reality of the here and now. Fact is, he did want to remain a Charger as he entered the final year of his contract in 2015. But if the franchise was truly destined for Los Angeles because of the stadium crisis in San Diego, then taking his large, beautiful family to Nashville would have had its merits as he wound down his career.

Mariota seemingly made sense for the Chargers -- he was rated as their top quarterback prospect of the 2015 class. Rivers was the face of the franchise, but Mariota would have provided a fresh face.

Rivers certainly made sense for Whisenhunt, who was in his second year as the Titans coach. The two men forged an immediate bond when Whisenhunt served as San Diego's offensive coordinator for 2013. Rivers was the NFL comeback player of the year that season, and completed nearly 70 percent (69.5) of his passes for 4,478 yards, 32 touchdowns and just 11 interceptions.

Whisenhunt became a hot commodity again, and chose the Titans over the Detroit Lions for his next head coaching spot in 2014. He was fired eight games into Mariota's 2015 rookie season and rejoined Rivers and the Chargers in January as offensive coordinator.

So why didn't a trade happen?

The Spanos family that owns and operates the Chargers ultimately wanted Rivers to remain the cornerstone of their franchise, especially as they navigate the rough waters of funding a new stadium or possible relocation. Mariota did have high draft grades, but rookie struggles often come with a price -- just ask Whisenhunt.

Mariota is now thriving in his second season, and he no doubt will get the big bucks from the Titans in a couple of years. Last August, the 34-year-old Rivers signed a four-year, $84 million extension with the Chargers with one stipulation -- he insisted upon a no-trade clause.

-- Chris Mortensen

The difference between the Cowboys and the Browns

There was once a time when Cowboys owner Jerry Jones had to be talked out of using Dallas' first-round pick on quarterback Johnny Manziel while being steered toward guard Zack Martin -- which left Cleveland to use one of its two first-round selections on Manziel.

Now Dallas and Cleveland square-off Sunday, and that draft is a prime example of why the Cowboys are 6-1 and the Browns are 0-8.

Since 2010, Dallas has picked 11 offensive players in the first four rounds of the draft, and nine of them (81.18 percent) -- Dak Prescott, Ezekiel Elliott, Tyron Smith, Martin, Travis Frederick and Dez Bryant -- are still on the team, the highest percentage in the NFL.

Ezekiel Elliott leads the league in rushing with 799 yards through Week 8. Andrew Dieb/Icon Sportswire

The Browns have picked 21 players in the first four rounds of the draft during that same stretch, and only eight are still on the roster (38 percent), which is the NFL's lowest percentage of offensive players picked in the first round that are still on those respective rosters. The players Cleveland picked in those rounds who no longer are on the team include Manziel, Trent Richardson, Brandon Weeden, Travis Benjamin, Jordan Cameron and Colt McCoy.

Not many teams have done a better job drafting than Dallas, which has become a model of stability and productivity. Meanwhile, no team in the league has squandered more picks and more opportunities, which is why the Browns are staring straight at the prospect of becoming the fifth NFL team since 1944 to go winless, joining the 1960 Dallas Cowboys (0-11-1), the 1976 Tampa Bay Buccaneers (0-14), the 1982 Baltimore Colts (0-8-1) and the 2008 Detroit Lions (0-16).

Once again, Cleveland is armed and loaded with multiple picks in April, including two in the first round. But if the Browns want to catch the Cowboys beyond Sunday, they have to start keeping up with the Joneses.

-- Adam Schefter

How soon should Cam Newton expect change?

A telephone conversation between NFL commissioner Roger Goodell and Carolina Panthers quarterback Cam Newton after a lower-leg hit by Arizona's Calais Campbell won't instigate renewed dialogue about the re-positioning of the referee, whose duty is to police quarterback protection.

That's a discussion already reserved for another day.

Currently, the referee lines up to the right side behind the quarterback, in part to have a better view of the passer's arm on a strip-sack fumble. However, those plays are now automatically reviewed by instant replay on a turnover, or by a coach's challenge on whether the quarterback's arm is coming forward.

Proponents within the league believe the referee should be positioned behind the quarterback's blind side to enable better enforcement of QB protection rules. The league's competition committee will take it up again in the offseason, according to Dean Blandino, the league's vice president of officiating.

"We have talked about that for a few years," Blandino said. "It doesn't apply to the Campbell hit because he comes up the middle, but there is some merit to it. We haven't seen significantly more missed calls on one side compared to the other in recent seasons but... with replay involved in the strip-sack, that is no longer a reason to keep [the referee] on the right side. [It's] something we will continue to look at."

-- Chris Mortensen

Charles stands out among a strong class of running backs

If Jamaal Charles' career is coming to a conclusion for the Kansas City Chiefs, he should be remembered as one of the pleasant surprises to come out of the 2008 draft class that included five first-round running backs.

None of those first-rounders were Charles, who was a third-round choice (No. 73 overall) by the Chiefs. Yet, the former Texas Longhorn has accumulated 7,260 yards rushing, 2,457 yards receiving and 63 touchdowns during his career. His 5.5 average per carry is the best in NFL history by a running back with that amount of work.

Only one of those first rounders has been more productive than Charles: Chris Johnson, who has racked up 9,537 yards rushing and 2,212 receiving yards with 64 touchdowns during stints with the Titans, Jets and Cardinals.

Matt Forte, who was chosen in the second round by the Chicago Bears, likely will finish as the most productive back of the class. He has 9,144 rushing yards, 4,279 receiving yards and 71 touchdowns. He remains the most durable among that class, still productive for the Jets.

The 2008 first rounders: Darren McFadden (fourth, Raiders), Jonathan Stewart (13th, Panthers), Felix Jones (22nd, Cowboys), Rashard Mendenhall (23rd, Steelers) and Chris Johnson (24th, Titans).

The Chiefs placed Jamaal Charles on injured reserve Tuesday, meaning the running back will miss at least eight weeks. Jason Hanna/Getty Images

Herm Edwards was in his final season as the Chiefs coach when the team selected Charles to be a complementary back to Larry Johnson.

"One reason people missed on him is because Texas had such a dominating college team he was out of a lot of games by the third quarter," said Edwards. "He was raw because he also had been a track guy and he was somewhat undersized. But, man, that guy could run and he ran with ease. Great kid. Coach's dream. Liked playing football. He worked at it, he learned how to play, how to run in this league and how to catch the ball, especially with Andy (Reid).

"Even with all the positives I can say about him, nobody imagined he would achieve what he has done. He deserves all the credit and recognition he can get."

-- Chris Mortensen

Tunsil's domination has quietly paved the way for Ajayi

Everyone can see the holes that Dolphins running back Jay Ajayi has been running through the past two weeks on his way to two straight 200-plus-yard rushing games. But not nearly as much attention has been paid to one of the lineman opening them: Laremy Tunsil.

Game tape of last week's win over Buffalo showed that the player Tunsil was blocking never made a single tackle, and didn't even come close to getting one. Tunsil wasn't just good; he was dominant. He was, in the words of one Dolphins' official, "ridiculously good. We were so lucky to get him. He was the best player in the draft."

But Tunsil slid for the infamous social media terrorism incident in which he was pictured wearing a gas mask, smoking from a bong. Teams kept passing him up and passing him up, until he slid to Miami at No. 13.

Laremy Tunsil has lived up to his worth as the No. 13 overall pick in the 2015 draft. Matthew Visinsky/Icon Sportswire

"He has been a great kid here," said the same Dolphins official. "We've had no issues with him, none. It's a joke what happened to him."

For now he is playing left guard in Miami, but eventually, in another season or two, the Dolphins will shift him to left tackle. They plan for him to be their left tackle of the future, their quarterback's blind side protector. But for now, Tunsil is getting ready for his first test against a stout Jets defensive front, trying to open more holes for the NFL's hottest running back.

-- Adam Schefter

Could Jacksonville turn to a former coach in the offseason?

Jaguars owner Shad Khan has said he's not making a coaching change now. At the end of the season, however, it could be different story.

If Jacksonville does make a coaching change -- and it's certainly looking like it will at the end of this season -- here's one name to keep in mind: former Jaguars head coach Tom Coughlin, the first head coach in that franchise's history.

Tom Coughlin spent the last 12 of his total 20 seasons as a head coach in the NFL with the New York Giants. Brad Penner/USA TODAY Sports

Coughlin still has a home in Jacksonville, his charity is based there, and he has publicly said he has not retired from coaching. The Jaguars would have to be willing to hire a 71-year-old coach, and that would appear to be the biggest catch and obstacle. But if they can accept that, they'd be getting a two-time Super-Bowl winning coach who knows the city well, has a history of getting production of its teams and would restore instant credibility to the franchise.

The Jaguars could hire Coughlin and have him groom a successor, until he is finished coaching and the coaching apprentice is ready.

It's important to note that there haven't been any conversations that have taken place between the two parties, but as one source close to the situation said last week, "It's not the craziest idea in the world."

-- Adam Schefter

Emptying out the notebook

Tennessee is still paying its former head coach and current Chargers offensive coordinator Ken Whisenhunt millions of dollars, and in return, he'll do everything within his power to beat the Titans on Sunday. Those checks won't let up anytime soon, either; Tennessee will continue signing them through the 2018 season.

One reason the Patriots moved on from linebacker Jamie Collins is the play of rookie linebacker Elandon Roberts. Watch Roberts on tape. He is blowing up opposing offensive linemen, and the Patriots want to see more of that.

How good has Raiders QB Derek Carr been? In his first 40 NFL games, he has thrown 70 passing touchdowns, the exact same number of passing touchdowns that Peyton Manning had in his first 40 NFL games -- only during that time, Carr has thrown 28 fewer interceptions than Manning.

It's been a rough stretch for Cardinals offensive tackle Jared Veldheer. Just last week he underwent finger surgery to repair ligaments, then, playing with that injury, he tore his triceps and now finds himself on injured reserve. The only person who feels worse than Veldheer about his injury is Cardinals QB Carson Palmer. Even with Veldheer on the field last Sunday vs. Carolina, Arizona allowed eight sacks. Palmer took his hits; the Cardinals offensive line is now taking theirs.

-- Adam Schefter