It's now confirmed that Sean Lee did in fact tear his ACL:
Cowboys LB Sean Lee has been told that he has a torn ACL and is expected to miss the entire season, per @Edwerderespn.— Adam Schefter (@AdamSchefter) May 28, 2014
The start of OTAs is supposed to be players getting reacclimated to practicing on a football field. Players tend to get eased into on-the-field activities in order to prevent unnecessary inures form occurring .
Brandon George of the Dallas Morning News reports the Cowboys believe Lee has a torn left ACL:
Dallas Cowboys sources believe LB Sean Lee has a torn left ACL. Still awaiting official word, however, from MRI taken late this afternoon.— Brandon George (@DMN_George) May 27, 2014
Nothing official from Cowboys, but league sources say Sean Lee told MRI confirms torn ACL in left knee and expected to miss 2014 season— Ed Werder (@Edwerderespn) May 28, 2014
Here's a video of Lee walking off the field with help from team trainers:
The Cowboys won't know for sure until they get back Lee's MRI. Lee got his left knee hung up before getting blocked by offensive guard Zack Martin in a non-contact drill. Lee previously tore his right ACL at Penn State.
"Sean has had to deal with injuries throughout college and also here in the NFL," Dallas Head Coach Jason Garrett said earlier Tuesday. "He really does everything he can to get himself ready to play. Unfortunately, he had to deal with a few of those things, but he's as mentally tough as an individual I've ever been around. Whatever the circumstances are, he always puts his best foot forward and strives to be his best. I don't anticipate this being any different."
The Cowboys signed Lee to six-year extension last summer worth as much as $51 million. It included a $10 million signing bonus. The base value of the deal is worth $42 million, and Lee could earn up to $9 million more if he plays in at least 80 percent of the snaps.
If Lee has indeed torn the ACL, he's at for at least the next eight months, meaning he's effectively out for the 2014 NFL season.