The subject on Doug Pederson’s Zoom call with reporters this week was cornerbacks, specifically Darius Slay. Someone asked the Eagles head coach, who was an NFL quarterback, what made him notice an opposing corner and cause him to throw away from him.

“I think No. 1 is, you definitely look at their size, their physical traits, their height, their weight, speed, length of arms,” Pederson said.

“Guys don’t have free releases against really good corners because of their length and their arm length and things like that.”

Pederson’s reference to the significance of a cornerback’s size was interesting, given the fact that he’s going to be starting one of the smallest corners in the league — 5-foot-9 Avonte Maddox — on the opposite side of the 6-foot Slay when the Eagles open the season against Washington on Sept. 13.

Maddox has done a solid job for the Eagles since they selected him in the fourth round of the 2018 draft. But it’s been primarily inside, at slot corner and at safety, where he started four games as a rookie.

Even though he played almost exclusively outside during his four years at the University of Pittsburgh, the Eagles drafted Maddox with the idea of moving him inside as a potential replacement for Patrick Robinson, who excelled in the slot for the Eagles during the team’s 2017 Super Bowl run.

“This is a guy that fits in well with our [defensive backs] room,” Joe Douglas, then the Eagles’ vice president of player personnel, now general manager of the New York Jets, said after drafting Maddox. “Even though he’s not the biggest guy, he will attack and support. He was a productive tackler in college.”

Maddox has made just four starts on the outside for the Eagles. He started the last three games of his rookie season on the outside because of an injury to Jalen Mills. And he started last season’s final regular-season game against the Giants because both Mills and the other starting corner, Ronald Darby, were hurt.

There are very few starting outside corners in the league under 5-10. The overwhelming majority are 6-foot or taller.

There’s a reason for that, not the least of which is that wideouts are bigger than ever. In this age of back-shoulder fades and 50-50 balls, it’s tough for a 5-9 corner to battle a 6-3 wide receiver.

Maddox doesn’t lack speed. He ran a 4.39-second 40 at the NFL Scouting Combine before the draft and jumped 37 inches. But he has just 29 1/2-inch arms (Slay’s are 32.2) and a 71 1/2 -inch wingspan (Slay’s is 75.6).

The starting corner job opposite Slay was expected to be a two-man competition between Maddox and 2017 second-round pick Sidney Jones. But the 6-foot Jones can’t stay healthy. He was bothered by injuries most of his first three seasons and is out again, with a “lower-body” injury.

Defensive coordinator Jim Schwartz is not blind to the challenges that face a 5-9 corner. But he thinks the other aspects of Maddox’s game, including his speed, physicality, timing, and jumping ability, will compensate for the fact that he’s going to be giving up a few inches to most of the receivers he faces.

Schwartz also is hoping that his beefed-up pass rush will help Maddox and the rest of the secondary by limiting the throwing time for opposing quarterbacks.

“Size matchups are always a concern,” he said. “But what I would say about Avonte is the only time he looks short is when he’s in the lunch line. When he gets on the field, he has never, in my mind, played small.

“He’s a physical player. He has great timing and ability to jump. He brings some things to the table that maybe some taller guys don’t have. He’s got great quickness and change-of-direction ability. He can get up to speed super-quick, which allows him to play a little bit different technique on the outside.

“And the thing he’s probably most deceiving with is he’s really strong. Let’s not confuse short with small. He’s matched up against bigger receivers his whole career.”

Maddox’s move to the outside probably isn’t permanent. If slot corner Nickell Robey-Coleman, who signed a one-year deal with the Eagles in March, moves on after the season, Maddox could slide back inside. Or he could eventually replace 30-year-old safety Rodney McLeod when he leaves. McLeod has two years left on his contract.

Maddox doesn’t feel his size puts him at a disadvantage on the outside. He played most of his college career on the outside and held his own against bigger wideouts.

“Between college and playing it here when they needed me to my first two years, I’m very used to it,” he said. “It’s helped me so much to have played so many different spots since I got here. It kind of puts everything in a bigger picture for me.

“When I’m outside, I know where my help is. When I’m inside, I know where my help is in the middle. It’s definitely a good feeling when you know where your help is. That can give you an edge on where you need to be when you’re defending a receiver.”

The tentative plan is for Slay, who signed with the Eagles in March, to “travel” with the opposing team’s top wide receiver a good deal of the time. But Schwartz also might determine matchups by size when he thinks Maddox might have problems with a taller receiver.

Slay, like Schwartz, thinks Maddox will be just fine.

“He’s quicker than a lot of guys,” he said. “He’s got a lot of bunny in him. He can jump pretty high for 5-9. And he can tackle. He’s aggressive. Quick feet. Smart player.

“He makes plays, man. I’m looking forward to playing with him. Because he’s been putting a lot of work in. Me and him have been communicating on and off the field. Working on drills and things. So I’m looking forward to seeing what he produces on the field this year. I’m excited for him.”