When Ed Reynolds sprinted toward the left sideline and settled under Tyrod Taylor's deep pass for a game-clinching interception in the Eagles' victory Sunday over the Bills, it didn't occur to Reynolds to contemplate the irony of the moment. He, quite literally, could have been anywhere else on Sunday.

He could have been playing for another NFL team, or idling on the practice squad for another NFL team, or doing nothing that had anything to do with any NFL team. The man is a Stanford alumnus, after all. He had options.

Yet the reason that Reynolds was even on the Eagles roster for Sunday's game, that he has seen so much time at safety over the last two games and has quickly become a valuable part of the Eagles defense, is something he couldn't do. He couldn't take a hint. After they selected Reynolds in the fifth round in the 2014 draft, the Eagles cut him, then signed him to their practice squad. After this year's training camp and preseason, they cut him again. And even though, according to both coach Chip Kelly and defensive coordinator Bill Davis, Reynolds had opportunities and offers to sign elsewhere, he chose to re-sign with the Eagles and bide his time on their practice squad again.

Why?

"Part of it is a little bit of pride," he said. "I wanted to prove myself here, the place where I got drafted. I had a good camp this year, a good offseason around these guys, and in the end, the decisions being made didn't work my way. But I felt like I had something to prove, coming back here and finally getting my chance. It took longer than I wanted to go out there and prove that I am a player.

"I'm not just a waste of a draft pick."

Reynolds' chance arrived Nov. 20, when the Eagles activated him after putting defensive back Jerome Couplin on injured reserve with a shoulder problem. In the Eagles' nickel defensive package, they prefer to have Malcolm Jenkins act as their slot cornerback. The alignment moves Jenkins closer to the line of scrimmage and forces Davis to insert another safety into the lineup to play deep. For most of the season, Chris Maragos, one of the Eagles' best special-teams players, had filled that role. But Maragos had not seen regular time at safety through his first five NFL seasons, and after the Eagles defense allowed a combined 83 points over back-to-back losses to Tampa Bay and Detroit, Reynolds replaced Maragos.

"We always felt he could play safety for us," Kelly said. "When we had the opportunity to get him out there, it doesn't surprise us" that he would play well.

The opportunity was a long time coming, though, in part because of Reynolds' academic career at Stanford. Even after having been drafted, he couldn't participate in any organized team activities with the Eagles during spring 2014, thanks to an NFL rule that prohibits players from attending OTAs until after they have completed their spring terms at college. Stanford is on the quarter system, so Reynolds had to stay in Palo Alto, taking a statistics class, finishing off his political science major ("I wasn't out there taking some [expletive]," he said), studying the Eagles playbook, watching film on his iPad.

"I wish I could have had that time back," he said. "It's so much different from actually putting your body through it and being around the team - how guys communicate, how guys work, what guys do. It was a setback, but like I said, it's no excuse."

It was just the first of two setbacks. He had a strong preseason, including a two-interception game in the Eagles' first exhibition against the Indianapolis Colts, and still, at the time it wasn't enough.

"I got the call and was somewhat in shock, frustrated - not so much mad at the guys upstairs, more just asking them, 'What more could I have done?' " he said. "For a long time, I was like, 'I'm going to come in and be professional every day, but they're going to know I'm not happy with the decision.' And I felt like that they respect that. They want a guy who's not happy just to be on the practice squad."

To keep himself ready, just in case he might join the active roster, Reynolds sat in with Jenkins and Walter Thurmond all season for film-study sessions, and the preparation paid off last week as he and Jenkins pored over tape of the Bills. They noticed how Taylor often forced the football down the field to wide receiver Sammy Watkins. "Every safety who we saw play with depth and good eyes had a chance at the football," Jenkins said.

Early in the game, Reynolds was late to break on a deep pass to Watkins, who caught the ball for a 47-yard touchdown. Late in the game, on the same play call, he was there waiting to intercept Taylor's pass.

"That's the growth you're looking for in young guys," Davis said. In every way possible, Ed Reynolds was exactly where he was supposed to be.