The Vikings' most significant move of the NFL offseason, made late Wednesday afternoon, means they'll be under the league's lowered salary cap when free agency starts on March 17.

It also means they'll have a new left tackle in 2021.

The team released veteran Riley Reiff on Wednesday afternoon, cutting the 32-year-old they'd initially hoped they would be able to bring back on a new deal that would lower his salary cap number for 2021. Instead, the Vikings cut Reiff in a move that saved them more than $11 million in cap space on the day the NFL set its salary ceiling for the 2021 league year.

After negotiations with the NFL Players Association, the NFL on Wednesday set its 2021 salary cap at $182.5 million per team, or $15.7 million lower than the 2020 figure.

Even though the amount is higher than it could have been — the league and union initially agreed to a $175 million floor for the 2021 cap in response to lost revenue from the coronavirus pandemic — the unadjusted cap is still nearly 8% lower than in 2020, representing the first time the NFL's spending ceiling has dropped since the 2011 lockout.

The Vikings, who will carry over $4.77 million in cap space for an adjusted figure of $187.2 million, have been planning for the reduced cap in 2021. The deal they gave Dalvin Cook, with a base salary of just $1.5 million this season, was written specifically with a lower cap number in mind.

General manager Rick Spielman had hinted last week at some tough decisions before the start of free agency. Reiff's release came eight days after the team cut tight end Kyle Rudolph and a day after it let go of kicker Dan Bailey, whose agent said he was unable to come to terms with the Vikings on a restructured deal.

The Vikings nearly let go of Reiff at the end of training camp, to make room for Yannick Ngakoue after they sent a second- and fifth-round pick to Jacksonville for the defensive end. Amid talks about a pay cut, Reiff was saying goodbye to teammates, expecting he'd be released if the Vikings and his agent couldn't reach a deal.

In the end, he decided to accept a $5 million pay cut, with the chance to earn $2 million back in playing time incentives. Reiff responded with one of his best seasons in Minnesota, playing every snap before he was placed on the COVID-19 reserve list before a Week 17 game against the Lions. He secured his first $1 million incentive, and after he fell just short of his second $1 million incentive because of the missed game, the Vikings reworked his deal to pay him anyway.

It seemed like a goodwill gesture that could lead to a new contract for Reiff, who was entering the final season of the five-year, $58.5 million deal he signed in 2017. He had a $5 million roster bonus due on March 19, and the Vikings seemed interested in working out a new contract before then.

Instead, Reiff enters a free agent market, where he'll be perhaps the second-best left tackle available behind San Francisco's Trent Williams. Meanwhile, the Vikings will continue remaking their offensive line.

They could move right tackle Brian O'Neill to the left side, while keeping Ezra Cleveland at guard. Or they could put Cleveland at the position Spielman hinted he could eventually play, making the second-year player the next left tackle and keeping O'Neill on the right side while looking for at least one starting guard.

The Giants on Wednesday released 31-year-old guard Kevin Zeitler, two years after they'd acquired him from Cleveland in a trade for Olivier Vernon. The Star Tribune reported at the time the Vikings had explored a deal that would have sent Everson Griffen to the Browns in exchange for Zeitler, but the Giants came through with a better deal.

In any case, the Vikings will again have significant changes at a position group they've needed to address almost every season of coach Mike Zimmer's tenure.

Guard Alex Boone was the team's big prize on the first day of free agency in 2016, at the beginning of a season where the Vikings would sign Andre Smith and try oft-injured former No. 1 pick Jake Long at tackle after Matt Kalil was lost to a season-ending injury.

Reiff and Mike Remmers signed five-year deals in 2017, and the Vikings spent a first- or second-round pick on a lineman in each draft from 2018-20, taking O'Neill in the second round before using their 2019 first-rounder on Garrett Bradbury and selecting Cleveland in the second round last year.

The Vikings' line ranked 18th in the league last year in ESPN's Pass Block Win Rate metric and finished 21st in Run Block Win Rate. Quarterback Kirk Cousins didn't miss a snap and continued a streak of not showing up on injury reports that dates back to Week 1 of the 2013 season. But Cousins was pressured on 38.6% of his dropbacks, more than all but three starting QBs in the NFL, as his tendency to hold the ball paired with a line that struggled to protect him at times.

He will have a new left tackle in Minnesota for the first time in 2021, as the Vikings' cap constraints led them to part with one of their captains.