Former NFL quarterback Carson Palmer saw the emotion in Andrew Luck‘s retirement press conference, like the rest of us.

But Palmer also thinks Luck didn’t mention everything on his way out the door.

The former Bengals, Raiders, and Cardinals quarterback told Peter King of NBC’s Football Morning in America that there might have been other things weighing on Luck beyond the physical pain.

“I think he was holding back a little bit,” Palmer said. “I remember going to rehab every day. I remember you feel guilt from your teammates. It’s hard when you’re Andrew Luck and you’re the face of the franchise. Everybody on your team looks at you in a certain light. I think the guilt and the shame—and in no way should he have ever felt guilt or shame for being injured—but that’s natural. When you’re so used to being the franchise quarterback, the face of the franchise, it’s impossible not to feel that guilt. I know I felt it. And I had days … I had one year, I blew my knee out [in Arizona in 2014]. We were 9-1. We were the No. 1 seed in the NFC. And my ACL popped and my season was over and I was going on IR. But I just remember walking through the locker room every day after that injury and you just can’t help it. You feel like everybody’s looking at you like ‘Ah man, he’s hurt.’ That guilt and that shame, I know Andrew felt it. I’m sure he wouldn’t admit it and he’s talking about other things, but that guilt and shame from your teammates is the most pain that he felt.

“When . . . you’re the guy that’s taking up 22 percent of the salary cap and the guy that’s on every ad around town, all those things that come with being Andrew Luck and knowing the way he was revered by his teammates and knowing the way he loved his teammates . . . I think all that weighed heavy on his heart.”

Considering the vicious beatings Luck took behind some substandard Colts lines, he didn’t have anything to be ashamed of being in pain. But those feelings were still real for Palmer, whose own career was defined by some big injuries of his own.