Two summers ago, as the Vikings opened Twin Cities Orthopedics Performance Center to fans for their first training camp there, Stefon Diggs’ face was nearly impossible to miss. It was splashed into every nook and cranny of the sprawling facility, from the exhibit in the new team museum celebrating the receiver’s iconic “Minneapolis Miracle” to the floor-to-ceiling picture of the play in the Vikings’ media center.

Fans applauded giddily as Diggs leapt between defenders to haul in deep throws from new quarterback Kirk Cousins in practice. Cousins gushed about how lucky he was to have two hypercompetitive receivers in Diggs and Adam Thielen. And after the Vikings left the practice field on a sun-soaked afternoon on the final day of July 2018, General Manager Rick Spielman pulled Diggs in for an embrace before giving the wide receiver the floor to talk about his new five-year, $72 million contract.

“Stefon, not only what he does for us on the football field, but when I was talking to his mother and how proud she should be of him as a man and how he reps his name, how he reps the Minnesota Vikings off the field as well,” Spielman said that day.

Whenever the NFL permits teams to return from the coronavirus scare and the Vikings begin their offseason program in Eagan, they might come back to a building that bears fewer artifacts from Diggs’ five seasons in Minnesota. The 26-year-old receiver himself will not be there after a Monday trade that shipped him to Buffalo along with a seventh-round pick in exchange for four Bills draft choices.

The deal seized headlines Monday, but not because of its suddenness. It came with an air of inevitability, after a year’s worth of events that had frayed the relationship between the receiver and the Vikings. On Tuesday, a day after the trade was done and a day before it could become official, the end of the ordeal allowed some in the organization a moment to breathe.

The 21-month journey from that July day to Monday’s trade can perhaps be charted alongside the shifts in offensive identity that took the Vikings from shotgun sets and spread formations to heavy personnel groups and a dogged commitment to the run.

At the time the Vikings paid Diggs, they were set to turn him and Thielen loose in an offense that would throw to set up the ground game. It started well enough, with Thielen tying an NFL record for eight consecutive 100-yard receiving games to start a season and Diggs catching 58 passes in the first half of 2018 as the Vikings began the year in playoff position.

Change in philosophy

But coach Mike Zimmer’s distaste for offensive coordinator John DeFilippo’s approach went from private to public in the second half of the year, and after Zimmer fired DeFilippo in Dec. 2018, the Vikings reorganized their offense around Kevin Stefanski’s collaboration with Gary Kubiak. Cousins went under center most of the time; the Vikings used multiple tight ends more and featured Dalvin Cook in the running game. The approach rankled Diggs early in 2019, and after Thielen again became the team’s highest-paid receiver in April 2019, Diggs skipped portions of the Vikings’ offseason program. During that time, sources told the Star Tribune, the receiver was angling for a trade out of Minnesota.

The contract Diggs signed gave the Vikings plenty of leverage, and the team held firm even as Diggs brooded. But after a second NFC North road loss dropped the Vikings to 2-2 in September, Diggs’ frustrations boiled over in the form of an absence the Vikings couldn’t whitewash.

After he skipped two days of meetings and practice following a loss to the Bears, sources said he was texting teammates he was done with the Vikings, fed up with a role that afforded him only 19 targets in the team’s first four games. Cousins publicly apologized to Thielen that week for not finding him downfield in Chicago; despite a few spats that both have chalked up to their competitive nature, the two always had seemed closer than Cousins and Diggs.

Zimmer closed practice Wednesday that week with an expletive-laden speech about Diggs’ absence (as team play-by-play announcer Paul Allen recounted on his radio show Tuesday) and the Vikings used their considerable leverage to get Diggs back in the building the following day. He surprised the team with an enigmatic news conference, during which he said “there’s truth to all rumors” about whether he was unhappy in Minnesota.

Shades of Harvin

But after he accepted more than $200,000 in fines for leaving the team, he bottled up his misgivings (at least publicly) for the rest of the season, posting 921 receiving yards in his final 11 games while becoming one of the NFL’s premier deep threats. It allowed the Vikings to table the idea of trading Diggs in the middle of the season, adopt a nothing-to-see-here public posture about the receiver’s future and surge toward the second round of the playoffs. Behind the scenes, though, it was clear Diggs’ feelings hadn’t changed. His cryptic social media actions — deleting every image of himself in a Vikings uniform from his Instagram account, posting pictures of himself working out in Cardinals gear — only stirred up more intrigue this offseason.

Much as he did with Percy Harvin in 2013, Spielman played his hand deftly, maintaining he would not trade a receiver whose desire to leave Minnesota was something of an open secret. He got three picks for Harvin (including a first-rounder) that year; he netted three picks (including a first-rounder) for Diggs this week.

Those picks come in a draft considered to be stocked with receivers, and the Vikings could find a player who fits better with the organization in 2020 than Diggs did in 2019. Draft picks carry risk, though, and as the Vikings found out with their plan to replace Harvin — signing Greg Jennings and trading up to take Cordarrelle Patterson — moving on from a known commodity isn’t always as easy at it seems.

Still, when the Bills came through with an offer for Diggs the Vikings deemed to be fair, they decided to deal away their most dynamic receiver from a year ago. As difficult as the move might have been from a football perspective, the events of the past year had gradually nudged the Vikings toward that conclusion.

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