Brandon Wade/Associated Press

Two years of Cary Williams and Bradley Fletcher patrolling the perimeters was enough for the Philadelphia Eagles. Williams and Fletcher were sent packing this offseason in favor of Byron Maxwell, who signed a massive free-agent contract to shore up the cornerback position.

Of course, simple arithmetic shows the Eagles subtracted two and only added one in that equation. At this point in time, it's still unclear who will start opposite Maxwell.

It will have to be settled at training camp this summer.

Philadelphia Pass Defense Stats/Rank YDS/ATT TD 20+ 40+ RATING 2014 7.8 (t-27th) 30 (t-28th) 72 (32nd) 18 (32nd) 91.6 (21st) 2013 7.3 (t-19th) 25 (t-14th) 62 (29th) 9 (t-14th) 84.0 (15th) NFL.com

According to Reuben Frank for CSNPhilly.com, Nolan Carroll has been working with the first-team defense as the No. 2 cornerback so far, leading many to believe the sixth-year veteran is the front-runner to win the job.

Carroll very well could be in the lineup come opening day. However, there's plenty of competition.

Throw Brandon Boykin's hat into the ring. Boykin has seemingly been overlooked as an option on the outside due to his size (5'10"), but as defensive coordinator Bill Davis told Geoff Mosher of CSNPhilly.com, that simply is not the case, and the nickel corner will have a crack at the vacancy as well.

And the Eagles didn't spend a second-round draft pick on Eric Rowe out of Utah to make him sit and watch. Head coach Chip Kelly forces rookies to earn their spot on the depth chart, which should help explain why Carroll is getting the first crack at the opening. It doesn't mean Rowe isn't in the mix.

Don't sleep on JaCorey Shepherd, the Eagles' sixth-round selection out of Kansas, either.

His odds to win the job aren't quite as good as Rowe's, but the consensus is Shepherd could be the steal of the draft. Jeff McLane of the Philadelphia Inquirer notes he had perhaps the strongest spring of any rookie on the team.

With that said, Shepherd is an unlikely candidate. No matter what Davis says, so too is Boykin, as the Eagles clearly prefer him in the slot. They'll have their chances, but a battle between Carroll and Rowe appears to be shaping up.

For what it's worth, Kelly went out of his way to praise Carroll when spring workouts opened. When pressed about the ongoing competition in the secondary, the head coach specifically mentioned the 28-year-old's strong offseason, per PhiladelphiaEagles.com:

Nolan Carroll has done an unbelievable job in the offseason. He's a guy that stands out in terms of what he's done in the weight room and some of those other things. ... I'm not slighting anybody by not saying them, but I just think Nolan is a guy, when you ask me about the defensive backs, that has really done a great job in the offseason.

Nolan Carroll Career Stats GMS/STARTS TKL PD INT 2014 16/1 32 4 0 2013 (MIA) 16/12 47 11 3 2012 (MIA) 14/10 53 5 0 2011 (MIA) 15/3 32 4 1 2010 (MIA) 13/1 3 2 1 NFL.com

Of course, there's a reason Carroll was available as a free agent last year.

When he finally got his chance to start in Week 17 against the New York Giants last season, he didn't look like the solution. According to Pro Football Focus, he was on the hook for four receptions for 82 yards in that contest, including a 43-yard completion.

That doesn't mean Carroll is incapable of improving. However, with 27 career starts in the NFL under his belt, he's something of a known quantity.

The question is whether Rowe, an unknown quantity, can prove he's the better option between now and September.

David Zalubowski/Associated Press

Rowe certainly has the tools to perform at the next level. He absolutely rocked the NFL Scouting Combine in February, finishing among the top 10 defensive backs in all but one drill, the 60-yard shuttle, according to NFL.com.

The 22-year-old timed second in the three-cone drill at 6.70 seconds, to go with 4.45 seconds in the 40-yard dash, 19 reps in the bench press and a 39-inch vertical.

Oh, and Rowe is an impressive 6'1", 205 pounds with 31 ½" arms—ideal size and length for an outside cornerback. Kelly couldn't stop gushing about what a perfect fit he thought this kid could be after the draft, as Geoff Mosher reported:

“Yeah, he’s a press corner,” Kelly said. “He’s that big, physical press corner that we’re looking for. Over 205 pounds, long arms, physical. ... “[Rowe] was the guy we wanted all along,” Kelly said. “I wouldn’t have been surprised if he went a lot earlier."

Eric Rowe College Stats GMS TKL PD INT 2014 12 59 13 1 2013 12 69 7 0 2012 10 64 6 1 2011 13 69 10 1 Sports-Reference.com

However, Rowe is somewhat inexperienced at playing cornerback. His first three seasons at Utah were spent lining up at safety, and while he excelled at corner as well his senior year—recording an interception and finishing second in the Pac-12 with 13 pass breakups—there's a big jump from college to the NFL.

Is Rowe going to be ready to start immediately? It's a fair question that the Eagles must attempt to answer this summer.

If not, there are worse things than going with a seasoned veteran like Carroll. Plus, at worst, Rowe should be able to play Carroll's hybrid role in Philadelphia's dime packages.

Then again, if the Eagles' secondary is going to take a big leap forward in 2015, it will require better play on the outside. Everybody seems to be expecting that out of Maxwell, but can either Carroll or Rowe solidify the opposite side of the field? That much remains to be seen.