Before the Vikings' trip to Detroit for last year's regular-season finale, receiver K.J. Osborn stood in his travel suit and looked in the mirror. He felt the weight of a trying rookie season that he wished to never revisit.

But he commemorated the moment with a Snapchat selfie, saved for his eyes only. It's an annual tradition for Osborn, who likes to look back every January and see how far he's come in the past year before starting a new one.

"When that picture pops up this year," Osborn said this week, "it'll be interesting to see how far I've progressed, where the team is, and things like that. I can look back on it and say last year, I made a commitment. I'm not going to feel like this. Hopefully, I'll be feeling great."

He's well on his way. The sure-handed Osborn has emerged as the No. 3 receiver, producing in critical moments in his second season after not playing a single offensive snap as a rookie fifth-round pick. He's leading the offense with 167 receiving yards, including his first NFL catch just two weeks ago in Cincinnati.

Osborn's ascension hasn't surprised coaches or teammates who saw growth in summer practices, but it seemingly came from nowhere for those who last saw him as a struggling punt returner on a 7-9 team.

"There was just a lot going on and it wasn't to my standard," Osborn said of 2020. "I wasn't even able to play offense, but even on special teams I was a lot better player than how I was performing."

Sitting with failure didn't work. By February, Osborn filled the schedule of his first NFL offseason with three different training companies and varied focuses from strength and conditioning to receiver-specific drills. Teammate Justin Jefferson was a regular training partner in Florida, where Osborn also formed a bond with Browns receiver Jarvis Landry during workout sessions involving many NFL players.

The 24-year-old Osborn was all ears around veterans who talked shop, but also life in the league and how to budget your time and money. Landry's approach to spring training sessions ahead of his eighth NFL season affirmed to Osborn how hard he needed to work.

"[Landry's] attacking," Osborn said. "Some guys when they have all that success, the work ethic drops. 'Juice' works like he's a free agent trying to make the team."

Refined footwork and releases from the line of scrimmage were evident as Osborn got open consistently in spring practices. Success carried into training camp, where Osborn suddenly appeared in the starting lineup when Jefferson and Adam Thielen suffered injuries. Hours of studying every receiver position in the playbook, from split end to slot to flanker, paid off. That built trust with coaches.

"It gives us a lot of confidence if someone goes down or we have to change personnel," offensive coordinator Klint Kubiak said. "K.J.'s going to figure out how to get it done. He's been impressive with his mental approach, but that's not just recently. That's how he approached the offseason."

Osborn's butterflies, felt when he first looked up in the huddle and saw running back Dalvin Cook and quarterback Kirk Cousins, subsided with every catch in practice. The extra work with starters formed a rapport with Cousins. They've connected on timing routes like the quick slants he caught for key gains before late field goals in Cincinnati and Arizona.

"Those are the kinds of plays as a quarterback when you see them made, it gives you a lot of confidence that you can throw the ball in there," Cousins said. "He's going to help us all season."

Even on those plays, Osborn can adjust. He caught two of Cousins' bullet passes with his hands behind him, like an over-the-shoulder catch. Ideally, Osborn said, he should've had his hands in front to pluck the ball out of the air.

Osborn's hands were behind him when he made the fourth-down catch that set up kicker Greg Joseph's late game-tying field goal against the Bengals.

"That's even harder than catching it regularly," Jefferson said. "He's been coming in clutch."

Many of Osborn's family and friends will be behind him Sunday at U.S. Bank Stadium, where they'll finally get to attend a Vikings home game and cheer on the newest receiver to emerge in Minnesota.

Osborn awaits another special moment after the game, when he'll get to swap jerseys with Seahawks tight end Tyler Mabry, his childhood best friend from sixth grade in Ypsilanti, Mich., through college at the University of Buffalo.

"Something we've looked forward to all our lives," Osborn said.

In that photo, they'll both have reason to smile.