Vikings' window to win is open ... for now

Nearby, teammates cleaned out their lockers at the end of a season that will perhaps be remembered most for an opportunity missed. Xavier Rhodes was asked to stop and ponder, at least for a brief second, the idea that time will not wait on these Vikings.

"No, man," the veteran cornerback said when asked if he was worried about the age of the Vikings defense. "We're fine like wine."

Aging might bring benefits in viticulture, but it's tended not to do so in the NFL. And as the Vikings try again to fortify their offensive line and chart a direction forward with their third permanent offensive coordinator in three years, they will also have to be mindful of the fact their window to win — at least with the core players they have acquired, developed and paid handsomely — isn't going to be any wider than it is right now.

Though Kirk Cousins only turns 31 this year — still relatively young for a quarterback — Riley Reiff will be 31 in December, and Mike Remmers turns 30 in April. Kyle Rudolph will be 30 in November, and Adam Thielen — who was 26 when he became a starter — turns 29 in August.

On defense, Everson Griffen turns 32 in December. Linval Joseph will be 31 in October and Harrison Smith turns 30 in February. Sheldon Richardson, who is scheduled to hit free agency in March, also turns 29 in November. Rhodes — who played 90 percent of the Vikings' defensive snaps in 2017 but dropped to 74 percent because of injuries in 2018 — turns 29 in June.

Pro Football Reference's Approximate Value metric, which attempts to put a number valuation on every player's season since 1950, can provide a general idea of how a certain group of players performed in relation to another.

From 2000 to '17, 834 defensive players posted an AV of 12 or better in a season; in other words, those players were generally among the top 50 defensive players in the league each year. Only 221 of those players were in their 30s, and just 95 were 32 or older.

Thanks to such quarterbacks as Tom Brady, Drew Brees, Peyton Manning, Ben Roethlisberger and Brett Favre, it's slightly more common to have top-end offensive players in their 30s; 235 of the 751 players with AVs of 12 or better were in their 30s, with 119 of them at least 32. The numbers make painfully clear, though, the point that aging players tend to feel most pointedly when contract negotiations come around: The NFL is a young man's league.

In each of the past three years, the Vikings have suffered from late-season defensive lapses that came either at the cost of their postseason prospects or a potential trip to the Super Bowl. In 2016, even after falling from 5-0 to 7-6, their playoff chances were still good enough that Adrian Peterson returned from injured reserve for a Week 15 home game. The Vikings gave up 759 yards and 72 points in back-to-back losses to the Colts and Packers, who won the division at 10-6 as the Vikings slipped to 8-8.

The 2017 season saw the Vikings defense allow 55 points in its last six playoff quarters, and last Sunday, after they had pulled within three points of the Bears late in the third quarter, the Vikings defense allowed Chicago to convert five third downs on a 16-play, 75-yard touchdown drive that consumed 9:05 and effectively ended their season.

Though it's difficult to know precisely what role fatigue played in the late-season lapses, it doesn't figure to play a smaller role as the defense ages.

"We didn't play great," coach Mike Zimmer said of the Vikings' 2018 defense. "We got back to playing pretty darn good there for the most part, but there's still some areas we have to get better there, too."

Though the Vikings could face a springtime decision on Griffen (scheduled to count $11.9 million against the 2019 salary cap), they are still likely at least a year or two from wholesale changes on defense. And while only five teams have more cap space committed to their 2019 roster than the $179.5 million the Vikings have tied up in contracts for next year, according to sources with access to NFLPA salary data, the team's pay-as-you-go structure means relatively few cap dollars are tied up in signing bonuses paid years ago to veterans. That allows the Vikings the flexibility to release or restructure the contracts of aging players.

That said, they have seen up close how difficult it is to maintain a dominant defense over time. The Seahawks team that won two consecutive NFC titles in 2013 and 2014 had already started to replace defensive starters by the time it beat the Vikings in the 2015 NFC wild-card playoffs, and of the mainstays on the "Legion of Boom," only linebacker Bobby Wagner started more than four games for the team that beat out the Vikings for one of the NFC's two wild-card spots this year.

With Zimmer and General Manager Rick Spielman headed into the final years of their contracts and standout players who have steadily moved into the primes of their careers, the Vikings can't count on things being the same forever. Their efforts to reassert themselves in 2019 will be aimed, in part, at making the most of a crop of talent that doesn't figure to ripen much more than it already has.

"[The reason for the drop-off in 2018] could be the expectation level [after 2017] and everybody believed it," Zimmer said. "It could be a lot of different things, but we're going to get it back."

Ben Goessling covers the Vikings for the Star Tribune. Twitter: @GoesslingStrib E-mail: ben.goessling@startribune.com