Cornerback might be the Eagles' deepest position, so a fourth-round rookie such as Avonte Maddox has to hustle not to get buried down the depth chart.

Ronald Darby, Jalen Mills and Sidney Jones have been the top three corners in this training camp. De'Vante Bausby, from last year's practice squad, has looked good, pretty much alternating in the nickel spot with Jones. Then there's Rasul Douglas, who started five games as a rookie last season, and another guy from last year's practice squad,  D.J. Killings, and undrafted rookie Chandon Sullivan, who came down hard after making an athletic interception in Monday's workout and went off to be checked for a concussion.

There also is Maddox, the smallest of the group, at 5-foot-9, 184 pounds, drafted 125th overall, from Pitt. Maddox was a standout on special teams in last Thursday's preseason opener, and the last two practices, he has worked with the first-team defense in that nickel spot, the one Jones and Bausby had been splitting.

"Like a lot of rookies he has ups and downs, but I think if you look at his trend line, he's trending up, which is a good sign," defensive coordinator Jim Schwartz said when asked about Maddox. "There's always going to be things that those guys struggle with over the course of camp. He's very competitive. He's been playing inside and outside. That's potentially something he might have to do. Maybe not, we'll see. But he's also done a really good job – I don't want to speak for [special teams coordinator Dave] Fipp – but he's done a really good job on special teams. We like where he's been so far."

In these last two practices, Maddox found that playing alongside Darby and Mills, with Malcolm Jenkins behind you and Fletcher Cox up front, is just a little different from running around out there with a bunch of other rookies and deep subs.

"You're out there with the Super Bowl champions on the field. It's just a different vibe," Maddox said. "They just communicate a lot, they know what's going on. You've got a lot more help in the back and you feel like a lot more [comfortable]."

"He competes, man. That's what you want, especially at that nickel spot," Mills said of Maddox.

"He's definitely going to be a playmaker," Darby said.

Maddox came late to football in high school, having seen himself as more of a baseball prospect growing up in Detroit. In the Eagles' media guide, asked his preference if he could play another sport, Maddox answered: "Shortstop, Detroit Tigers."

Maddox didn't play much nickel at Pitt, but he is an eager learner.

"It's a challenge, but I'm up for any challenge," he said. "I'm learning every day at the nickel spot, from leverage, being able to know what's going on formation-wise."

Maddox said his goal is to "compete … and make sure these guys can trust me here."

Coaches have given him some film cut-ups of Patrick Robinson, who played the nickel extremely well last season for the Eagles before going to New Orleans in free agency.

"He knew what was going on. He's got good fit-work [angles] at the line, he kind of knew good leverage," Maddox said of Robinson. "If you know where to be at, at the right time, you don't have to work as hard."

Maddox is strong as a blitzer – he notched four sacks as a Pitt senior – and came close to blocking a Steelers extra point in last week's game.

"I was right there. I bent across, I got skinny, I laid out," Maddox recalled. "[Kicker Chris Boswell] just got it up. … If I take an extra step, I probably get it."

Maddox blocked a PAT at Pitt, and thinks he can block more.

"You gotta get around that corner, bend that [edge blocker's] arm. … You gotta be ready to lay out," he said.

For a backup cornerback, special teams can be the key to making the team, and then to being active on game day. Here, Maddox has an advantage. Most rookies come to the NFL having been stars on their college teams, and not having played much special teams. Maddox was one of the Panthers' top players, but he said he played a strong special teams role until his senior year.

Maddox said he can play gunner, and can hold up the gunner for the return team. He also returned a kickoff 89 yards for a touchdown against Youngstown State in 2015.

"He played really, really good on special teams," against the Steelers, Mills noted. "Fipp gave him some praise on a couple plays. … If Fipp's giving a rookie praise, that doesn't happen too often."