EAGAN, Minn. — Terence Newman has seen tens of thousands of plays in his career, including the 2,272 defensive snaps he's been in on since joining the Vikings in 2015.

It's safe to say there isn't much that fools the Vikings cornerback when he steps on the field these days.

"He's probably seen just about as much as I have," Vikings Head Coach Mike Zimmer, who has been in the NFL since 1994, quipped about Newman earlier this week.

Newman is two weeks away from entering his 16th professional season. With youngsters Mackensie Alexander and Mike Hughes hampered by injuries this week, the Vikings have turned to their most seasoned veteran to line up at nickel cornerback.

While Newman may not be as fast as he used to be, he is just relying on is head a little more.

Actually, make that his eyes.

Newman said slot cornerbacks are closer to the middle of the action. Meaning they better pay close attention to everything going on just a few feet away from them.

"You have to get in the runs, you have to play pass. You have to make checks and communicate … it's kind of a jack-of-all trades [position]," Newman said this week about playing at the nickel spot. "You've got more space inside versus outside … I think you just have to get a feel for it and train your eyes a little bit more.

"On the outside, you just have a guy in front of you that you're looking at. On the inside, there's so many things that could happen and you have to change what you do," Newman added. "You could be on one guy and have to go to another guy. You're in the run fit a lot of the time so you have to see what's going on with the run, as well as dissecting whether or not it's a pass. It's important to have good eyes."

Vikings wide receiver Adam Thielen sometimes goes against Newman in practice. The All-Pro wide receiver said going against a cerebral player is actually tougher than one who is ultra-athletic because the smart cornerback has a better grasp of what the offense is trying to do.

"I think a smart guy in the slot is helpful," Thielen said. "I think understanding route trees and route combinations, because in the slot you're getting more combination routes than just 1-on-1 matchups. "

Those who have known Newman over the years aren't surprised he has adapted his game to be able to play in the NFL this long. 

Vikings safety George Iloka, who signed with Minnesota on Wednesday, played with Newman in Cincinnati from 2012-2014.

"He's still a vet, but he was a vet then as well," Iloka said. "When I came in as a rookie, he was just someone that you could lean on. He was dependable as a player, and he just did everything right on and off the field.

"He's very knowledgeable, and you could come to him about anything. He plays corner and nickel and he could tell you about the safety," Iloka added. "I think that tells you about him as a player and as a man, that he takes pride in his craft and he takes pride in understanding and learning the system. He helped me out a lot."

Newman is already the league's oldest defensive player but will turn 40 years on old Sept. 4. He'll join a handful of players 40 and older around the league, a group that includes quarterback Tom Brady and kicker Adam Vinatieri.

But as the season nears, Newman sounded downright chipper when talking about how his body feels after the grind of training camp.

"I feel great. I increased my reps a little bit this week but feeling good," said Newman, the fifth overall pick in the 2003 NFL Draft. "It definitely helps when you have things you need to work on.

"The more reps you get, the more you can work on those things," Newman added. "You watch film and see the progression and figure out, 'OK, this is what I need to work on.' But I'm feeling good."

Zimmer said the Vikings have kept close tabs Newman in recent weeks as the cornerback prepares for what he has said is his final NFL season.

Newman did not play in Minnesota's preseason opener and played just nine snaps against the Jaguars in the second preseason game, but Zimmer said he expects Newman's game to ramp up over the next few weeks.

"This last game when he was in, that wasn't his best game that he's played, so I feel like he's a little bit rusty because we've been taking care of him," Zimmer said. "His mental capacity with football has really helped him maintain being able to play.

"I watch him very close every day, and I still see a lot of really, really good qualities with him – with his acceleration, his techniques and things like that," Zimmer added. "He'll get a few more plays this week."