CHIP KELLY has rolled the dice so many times this offseason that I have to believe he's developing carpal tunnel syndrome.

He traded his starting quarterback for a guy coming off back-to-back ACL injuries (Sam Bradford). He traded his star running back for a linebacker who also is coming off an ACL injury (Kiko Alonso).

He gave $25 million in guaranteed money to a free-agent cornerback with 17 career starts (Byron Maxwell). He signed a guy to play safety who has never played the position and has missed 42 games due to injury the last four seasons (Walter Thurmond).

He showed the door to both of his starting guards, who had a combined 202 career starts.

On the eve of training camp Saturday, Kelly went back to the craps table and rolled the dice one more time, trading away one of the league's better nickel corners, Brandon Boykin, for a conditional 2016 fifth-round pick.

That pick could be upgraded to a fourth-round selection if Boykin plays 60 percent of the snaps next season for his new team, the Pittsburgh Steelers. But still, considering the Eagles were already going to have three new starters in their secondary this season, was it wise to get rid of one of the only reliable guys you had on the back end last year?

Kelly thinks it was.

He thinks it was for a couple of reasons. For one, Boykin is entering the final year of his contract, and given his frustration over not being given a chance to compete for a starting corner job, hell would have frozen over before he would have re-signed with the Eagles.

For another, Kelly feels that thanks to the acquisitions the Eagles made in free agency and the draft, they now have enough depth and position versatility in the secondary to offset the loss of Boykin.

"We have a lot of depth at that [cornerback] position," Kelly said. "[The trade] speaks more to our confidence in Maxwell and [Nolan] Carroll and [Eric] Rowe and [JaCorey] Shepherd and [E.J.] Biggers and [Jaylen] Watkins and [Denzel] Rice.

"We're going to have to make some tough decisions at corner, and we're not going to be able to keep them all. We've got nine and we're probably going to keep five. We didn't want to get to the end of camp and be releasing somebody when we had a chance to make a trade and get something on the other end [and didn't do it]."

Kelly said the Steelers have been interested in Boykin since the draft. But it wasn't until they were willing to make the conditional pick a fourth-rounder if he played 60 percent of the snaps that the Eagles were willing to deal.

"That's the part that kind of put it over the top for us," Kelly said. "Their nickel last year [Brice McCain] is with Miami. But their nickel last year played 60 percent of their snaps. So we thought it was too good a deal for us to turn down."

Boykin is the perfect nickel. While the 5-10, 185-pounder didn't have the length the Eagles prefer on the outside, his quickness, instincts and intelligence were tailor-made for the slot.

He played a ton of nickel at the University of Georgia, which was one of the main reasons the Eagles gobbled him up in the fourth round of the 2012 draft.

During yesterday's first training-camp practice, Shepherd, a rookie sixth-round pick, took all of the first-team nickel reps and appears to be the leading candidate to replace Boykin. He didn't play a single down of nickel at Kansas but has been a quick study.

"We're really, really impressed with him," Kelly said. "We're excited about his development and his growth."

"It's mostly [learning] the run fits," Shepherd said of the adjustment to playing nickel. "You have to know the play call as far as when you have run fits and when you don't. And I have to be a lot more aware of who I'm working with [at nickel]. If I'm working with a linebacker or a safety or a corner. At corner, usually just a corner and safety work with each other. But a nickel, I could be working with one or two or all three.

"But I learn pretty fast. I'm a fast learner. And the fact that I'm somewhat athletic is making it a lot easier for me."

Said safety Malcolm Jenkins: "You've got to use a little more of your brain inside. He's a smart young guy. He's asking the right questions and putting in the work and doing the extra stuff to learn that [position].

"It's really just about, you have the sideline on the outside [to help you]. Now, [inside] it's about [knowing] where your help is and knowing that for each defense. He seems to be grasping it. He stepped in today and didn't look nervous at all."

During the spring, Shepherd relied on Boykin to help him learn the intricacies of playing nickel. Constantly picked his brain. Mirrored him in the teaching portion of workouts.

"It does suck that I don't have him to go to with questions," Shepherd said. "But we do have older guys who have played some nickel too. So I can use them if there's something I don't understand."

He said he also won't hesitate to call Boykin if he has to.

"I let him know that if I got in trouble and somebody can't help me here, then I'm going to reach out to him and ask him," Shepherd said.

While there still are plenty of questions about the Eagles' secondary, Kelly and personnel director Ed Marynowitz have assembled a versatile unit that can play all over in sub-packages.

Both of the safeties, Jenkins and Thurmond, are former corners who can drop down and play nickel. Maxwell has played nickel. Carroll, who will compete with rookie Rowe, a second-round pick, for the other starting corner job opposite Maxwell, has played nickel and spent last year as the dime linebacker. The 6-1, 205-pound Rowe has played both corner and safety and is expected to be used in matchups against bigger tight ends and wide receivers.

"It's by design that we have guys like that," Jenkins said. "So that we can have depth, for one. And then have some flexibility as far as [being able to play] different packages.

"Everybody except for a couple of our safeties play multiple positions. That just gives us so much more flexibility, so much more depth and quality players at each position."