LAWRENCE — James Sosinski’s offseason lasted just one day, but it was nevertheless a longer break than the two-sport Kansas athlete anticipated.

It wasn’t, however, a 24-hour window the tight end-turned-forward could enjoy.

“I was sick,” said Sosinski, who flew home with the eliminated men’s basketball team on Easter Sunday and found himself sidelined with a mystery illness the following morning. “I was supposed to be (with football), actually. (Monday) was the first day of pads and I was sick.”

Never able to identify the cause of his brief bug, Sosinski speculated the shift in climate from San Antonio, the site of the Jayhawks’ season-ending defeat, to Lawrence, the location of the football program’s spring practice period, likely played a role.

Sosinski could also no longer count on the spotlight of the Final Four to provide warmth.

A tight end for David Beaty and the KU football team, Sosinski began practicing with Bill Self’s men’s basketball squad in late November and officially joined the program as a walk-on the following month. The 6-foot-7, 250-pound “fire hydrant,” as teammate Mitch Lightfoot dubbed him, was a welcome sight for the frontcourt-thin Jayhawks and served mostly as practice depth, though he did appear in seven contests.

One of those appearances came in the Jayhawks’ season-ending defeat to Villanova, a 95-79 drubbing that got out of hand early. Sosinski saw the court in the game’s final minute and, with 17 seconds remaining, successfully converted his only field goal attempt, a jumper.

While the outcome was a downer for KU fans, Sosinski’s cameo provided a thrill for his football teammates watching along at home.

“A couple of us buddies were just watching the game and it was like, ‘Oh! It’s SoSo,’ “ said senior linebacker Keith Loneker. “We were pretty amped to see him come out and get some playing time.”

Sosinski finished the season 3 for 3 on his field goal attempts.

“He’s on the all-time list now as the highest field goal percentage leader in KU basketball history,” joked senior wide receiver Ryan Schadler, “so that’s kind of cool to see.”

Back to a full-time football role, Sosinski has refocused himself entirely to the gridiron. He packed on 20 pounds over the summer thanks to the team’s strength and conditioning program and a heavy diet of eggs, bacon, bagels and protein shakes.

“That dude comes off of basketball season, he is as skinny as a road lizard. He was skinny,” Beaty said. “He worked his tail off. I think being with Bill and those guys really helped that guy a lot. His work ethic has been terrific, really has. Love watching him develop.”

A former scholarship quarterback at UMass, Sosinski transferred to South Mountain Community College in Phoenix and averaged 19.1 points and 12.6 rebounds for the school’s basketball program before converting exclusively to football and again transferring, this time to KU.

Sosinski didn’t see the field in his first year with the Jayhawks, in part because of a nagging foot injury, but the junior could be a difference-maker this go-round for a group facing a high-stakes season.

“I think there is no ceiling (for me),” said Sosinski, who is listed as one of two Jayhawks competing for the second tight end spot ahead of the team’s 6 p.m. Saturday opener against Nicholls State at David Booth-Kansas Memorial Stadium. “Obviously, football is my main goal because I only had one day off after the Final Four, so when I got back here I was just ready to go.”

Responsible for covering Sosinski at times in practice, Loneker described the Gilbert, Ariz., native as a dangerous weapon in the passing game.

“His arms feel like they just never end. They feel like they just keep going higher and higher to go get the ball,” Loneker said. “His body is not your typical tight end body -- he’s 6-7, and there’s guys like that, but you don’t see ‘em everywhere, so it’s great for him. He’s pretty fast too -- he’s got some long strides. It’s great for him to just be that big target and be able to get the ball, and he’s got great hands, too.”

While it may seem peculiar to claim playing for a basketball team helped a football player’s physicality, Sosinski believes his “surreal” stint with Self’s squad did just that, citing battles in the trenches against 7-foot, 270-pound center Udoka Azubuike as key.

“That’s the only way I could beat him. He’s way taller than me and way better, so I felt like the only way I could beat him was my strength,” Sosinski said. “It was hard every day doing it, but I felt like it was good work. Honestly, Doke is probably one of my great friends here now and I hang out with him a lot.”

Football, Sosinski says, is where his heart is, so when Beaty asked him to address the team upon his return in the spring, he didn’t hesitate. His brief address touched on the culture of the men’s basketball program -- winner of 14 straight regular season Big 12 championships -- and how the struggling football program can adopt some of that swagger.

At least in one small way, that process has already begun.

“In basketball, we’d always break (huddles) down during the season, ‘Big 12 champs,’ “ Sosinski said. “This year (in football) we’re breaking ‘em down, ‘Shock the world.’ Just keeping that goal in mind. Whenever you’re working hard, just keep that goal in mind.”