Four days after drafting a first-round cornerback, the Vikings doubled down on that position Monday for their top-flight secondary.

The team re-signed Terence Newman, who will turn 40 in September, and exercised the fifth-year option for Trae Waynes. The two moves are foundational: The first locks up the league’s oldest defender and mentor for the Vikings’ young secondary for at least another season. The second keeps an up-and-coming talent in the fold through at least 2019.

Newman will be just the second defensive back in NFL history to play at 40 years or older, according to the Pro Football Hall of Fame. At this rate, he has a shot at the position’s age record, set when 42-year-old Darrell Green played for Washington in 2002.

While Newman’s role on the field has declined, his roles off it have been just as important. Cornerback Mackensie Alexander has credited Newman for helping him mature, and Newman has also been helpful in bringing along Xavier Rhodes, now one of the league’s best corners.

“He’s a vet,” Rhodes said. “He’s a guy who can help you realize the littlest things.”

It remains to be seen how his role on the field will develop, after Alexander played about one-third of snaps last season and the team drafted Hughes at 30th overall.

Waynes will be starting at left cornerback, where last year he was one of the most targeted corners in the league. While his $9 million option for 2019 is guaranteed for injury only, he’s expected to stick around after coming on strong at the end of last season. Waynes’ progression got to the point where it allowed coach Mike Zimmer to better balance the coverage schemes.

“The second half of the year he’s played really well,” Zimmer said late last season. “There was a lot of times earlier in the year I was helping him a lot. I’m not doing that very much anymore.”

Quarterbacks avoid Rhodes, so Waynes was thrown at 102 times, the fifth most among all cornerbacks, according to Pro Football Focus. He finished with 11 pass deflections, two interceptions and a sack. He allowed only three touchdowns, according to PFF. Waynes’ improvement also included limiting penalties. He was flagged four times — down from seven in 2016 and only once after Week 5.

“He’s been out there on his own, and I actually think that’s part of the reason why the defensive numbers have come down quite a bit,” Zimmer said. “Because of the way these corners cover on the back end.”

Waynes’ additional year means the entire starting Vikings secondary is under contract through at least the 2019 season. That’s when contracts will be up for Waynes and safety Andrew Sendejo.

The Vikings finished with the NFL’s second-best pass defense, allowing 192.4 yards per game last season.