ALLEN PARK, Mich. -- Although no current Detroit Lions players were on site for any offseason workout programs, the practice facility was open for one of the greatest players in franchise history on Sunday.

Hall of Fame receiver Calvin Johnson returned to host a high school football camp, welcoming all positions, in partnership with the Lions.

Johnson's connection with the Lions has been trending up lately as the franchise tries to repair its relationship with him. He was spotted on the sidelines during an OTA session in late May in addition to returning for the last day of mandatory minicamp Thursday.

He said, "it feels good to be around the guys," but doesn't have a designated role with the team.

He credits Lions chief operating officer Mike Disner for helping mend the relationship, although he says there's still work to be done.

"I always say Mike Disner's been a huge part of bringing this thing back together with the team," Johnson said. "So I'm appreciative of them, appreciative of the whole organization allowing me to have it here and collabing with me in doing that because it's a heck of an experience for these kids."

Johnson's relationship soured in Detroit after being forced to pay back a little more than $1 million to the Lions upon his retirement after the 2015 season. However, he has been around the team facility more than usual this offseason, even joining Lions great Barry Sanders in welcoming Detroit rookies Jahmyr Gibbs and Jack Campbell once they arrived in Michigan with their families.

"I don't know, I just want to be here for the team, and for the players," Johnson said during Sunday's camp. "I've got a lot of experience, on and off the field, so I'd love to share it."

Fellow Hall of Famer Warren Sapp was among the many former pros to assist at Johnson's camp Sunday. Sapp called it "a beautiful thing whenever an organization brings back one of their signature players."

"Barry didn't end too well either up here, so it's just one of those things where we're grown now," Sapp told ESPN. "Let's let bygones be bygones and let's just move on because it's a better and bigger purpose out there.

"It's always good whenever you do right by your legends because we were sitting underneath the Doug Williams curse [in Tampa Bay] until [head coach] Jon [Gruden] brought him on the sidelines with us, trust me. I saw Doug the other day, too, and we talked about it, trust me. You sit underneath those curses with your former players that you didn't do right. Yes."

Johnson, 37, still holds many franchise records, including most receptions (731), receiving yards (11,619) and touchdowns (83) despite retiring from the NFL after just nine seasons (2007-2015).

Lions coach Dan Campbell still lauds Johnson as an "unbelievable teammate" despite his massive success. Campbell played alongside Johnson in Detroit in 2007 and '08 and says he welcomes his feedback and advice as the Lions look to build off their 9-8 finish last season.

"To have him out here, you know, there's a level of respect that will always be there for me, but even our players, they know who he is," Campbell said during OTAs on May 25. "Anybody who has played around this game you know; they understand the type of player he was. From a production standpoint.

"I wish they knew what kind of teammate he really was; you know, I wish they had a chance to actually play with him. But it's good to have him here. It is. It's good. It's good for us."