There goes the old man's ankle.

Green Bay Packers linebacker Brad Jones didn’t make a lot of plays in Sunday’s win against the Minnesota Vikings, but he did make one big one.

Jones hit Vikings quarterback Brett Favre from behind on the play that would turn into Favre’s first interception on a three-interception night. On the play, Favre’s foot got caught under Jones and bent backwards, re-injuring his surgically repaired ankle.

Favre limped around and finished the game, but today it was revealed Favre has a stress fracture and an avulsion fracture in his heal. Favre wore a walking boot around the Vikings’ facility, Monday, and the injury puts his chances of starting next week in serious jeopardy.

“He’s got to be able to do all the things that his position does,” Vikings coach Brad Childress said. “You can’t put a guy that’s a sitting duck out there. His competitive nature I’m sure will come into it. But a lot of times you’ve got to protect people from themselves.”

If Favre doesn’t start it would end his streak of consecutive games at 291. He wasn’t available to the media on Monday, but suggested he might not be able to play after Sunday’s loss.

“If I can play but not be effective, then it’s not worth playing,” Favre said. “I hope I use good judgment, so we’ll see. I’m no spring chicken anymore. I don’t heal as quickly.”

This may be just the excuse Childress needs to sit Favre. The 41-year-old quarterback hasn’t played well even when he’s been healthy this season. He’s thrown 10 interceptions against seven touchdowns and also has lost four fumbles.

In short, he looks like the old man he is and the Vikings are 2-4, which puts them only one game ahead of the lowly Detroit Lions in the NFC North. You can’t tell me Tarvaris Jackson couldn’t have pulled that off.

In a SportsNation poll, 79 percent of respondents said Vikings fans should be concerned about Favre.

Good thing you came back for one more year, Brett.