Eden Prairie, Minn. ? Brett Favre’s ironman streak has endured a litany of injuries and even a pair of premature retirement news conferences.

Perhaps this is the week that, finally, Favre’s health prevents him from playing.

The 41-year-old Minnesota quarterback has a stress fracture in his left ankle that could end his NFL-record streak at 291 consecutive games started — 315 including the playoffs.

Vikings coach Brad Childress said Monday an MRI on Favre’s foot revealed the stress fracture as well as an “avulsion” fracture in the heel bone. An avulsion fracture occurs when a fragment of bone is torn away by a tendon or ligament. Childress said neither injury requires surgery.

“He’s got great pain threshold and also great competitive zeal,” Childress said, succinctly summing up Favre’s legacy of durability.

Favre is also the subject of an NFL investigation into allegations that he sent lewd photographs and suggestive messages to a female New York Jets employee in 2008, a development that first put his streak in danger with the possibility of a suspension under the league’s personal conduct policy. NFL spokesman Greg Aiello said Monday there was nothing to report about the investigation.

For this week, it appears Favre’s biggest problem will be figuring out a way to heal fast enough to face New England on Sunday.

“He’s got to be able to do all the things that his position does,” 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.”

Favre had arthroscopic surgery on the ankle in May, and he received a series of lubricating injections in the joint at the beginning of the season. The ankle has bothered him at times this fall, but he hurt it in Sunday’s 28-24 loss at Green Bay as he was being tackled from behind while throwing his first of three interceptions against the Packers.

Favre was limping around during the game and walking gingerly afterward, and Childress said he was wearing a walking boot around the practice facility on Monday to make him more comfortable.