Head coach Jim Caldwell hopes Detroit Lions can patch things up with retired Calvin “Megatron” Johnson

In this Nov. 24, 2013, file photo, Lions wide receiver Calvin Johnson watches during an NFL game against the Tampa Bay Buccaneers in Detroit. Johnson told the Detroit Free Press that he felt he should have been treated better as he left the Lions. The star receiver retired following the 2015 season. (AP photo)

ALLEN PARK — Detroit Lions coach Jim Caldwell hopes the franchise’s relationship with Calvin Johnson will eventually improve.

Johnson told the Detroit Free Press over the weekend that he felt he should have been treated better as he left the Lions. The star receiver retired following the 2015 season.

Caldwell spoke to reporters Wednesday at an organized team activity, and he said the organization — from owner Martha Ford on down — was concerned about Johnson’s comments.

“We’re all concerned about it, anytime that we hear that one of our alumni is not happy,” Caldwell said.

“Particularly how we feel about our alumni around here. One of the things I think you’ve probably noticed, at least since I’ve been here — our practices are open to all our alumni. They can come anytime, any day.”

Johnson didn’t go into specifics with the Free Press about what treatment by the team left him unsatisfied.

“I don’t even like to talk Lions too much just because the way our relationship ended,” he said.

Johnson played his entire nine-season career with Detroit.

“I just didn’t feel like I was treated the way I should have been treated on the way out. That’s all,” he said. “I mean, it’s all good. I’m not tripping. I don’t feel any kind of way, just hey, that’s what they did.”

Johnson caught 88 passes for 1,214 yards and nine touchdowns in his final season. He retired at age 30, bringing back memories of the way Barry Sanders stopped playing when he was still one of the game’s stars.

“Playing in the National Football League for a team is like a family. Family sometimes have disagreements. They look at things a little differently,” Caldwell said.