Third-string quarterback Taylor Heinicke is expected to miss at least two months after injuring his ankle this month, a source confirmed.

After a late-night movie, Heinicke and a friend realized they were locked out of his friend's apartment. Trying to enter, Heinicke kicked through a glass pane in the door and severed a tendon in his left ankle. He underwent surgery and is expected to start the season on the non-football injury list.

On a rolling scooter, Heinicke reported to training camp in Mankato on Thursday with a cast on his left leg.

Heinicke made the Vikings roster as the third-string quarterback last year, undrafted out of Old Dominion. He was inactive for all 17 games.

The Vikings added quarterback Joel Stave, a Wisconsin product, as an undrafted free agent this spring.

The Pioneer Press first reported Heinicke's injury.