Source: Taylor Heinicke severed tendon helping friend break back into apartment

MANKATO, Minn. -- Minnesota Vikings quarterback Taylor Heinicke is expected to start the season on the non-football injury list. He could miss up to three months after he severed a tendon in his left foot while trying to help a friend get back into his apartment earlier this month.

Heinicke and his friend returned from a movie to find they were locked out of the friend's apartment, a league source said, clarifying earlier reports that the apartment was Heinicke's.

Heinicke tried to kick open the door and cut his foot while breaking through the glass pane on the door. There was no foul play or substance abuse involved in the incident, the source said.

Heinicke, whom the team signed as an undrafted free agent in 2015, made the Vikings' roster as the third quarterback after an impressive preseason last year. His stock in the organization had improved following a solid spring, and his similarity to Teddy Bridgewater made him an appealing option to back up the third-year QB.

Now, the Vikings will hope to get Heinicke back by the middle of the season.