When Derek Carr went down with a broken fibula in Week 16, the Raiders' season effectively ended. Sure, they still went to the playoffs, but their hopes went down when Carr hit the deck. 

The hit that resulted in Carr's injury came from Colts defensive end Trent Cole, who beat left tackle Donald Penn around the edge. Penn slipped while trying to block Cole, who grabbed onto Carr's leg while dropping him to the ground. 

Though Penn himself said a few months ago that Carr told him that he's nearing 100 percent health, the play that resulted in Carr's injury still sticks with him. 

"You've got to try not to think about it too much," Penn said, per the Las Vegas Review-Journal. "It happened. You wish you could go back and get it back. I've done that same [pass] set I don't know how many times on that same field and never just slipped out of nowhere. I took a little step. I'm not going to put it on myself. I should have been able to do something better. You know me: I'm not going to blame the slip for happening."

Penn knows what he should have done to prevent it. 

"I should have held on [to Cole] and brought him down with me," he said. "That play sticks with me. I'm going to try to do whatever I can do better to make sure nothing like that ever happens again. I've never gotten a quarterback hurt before in my life since I've been playing. None of my quarterbacks ever got hurt. That was the first. That's something I take pride in, and I'm going to try my hardest to make sure it doesn't happen again."

Penn's one of the better players in the league at his position, and Carr was one of the best-protected quarterbacks in the league last season. He's also taken harder hits than the one that resulted in his injury. This is something that happened, but not necessarily something that was anyone's "fault," so it's good to see that Penn is at least not beating himself up too much over it.