EDEN PRAIRIE, Minn. -- Minnesota Vikings left guard Brandon Fusco is questionable for the game against San Diego on Sunday.

Fusco missed practice Wednesday and returned on a limited basis Thursday after going through the league's concussion protocol. He participated fully in practice Friday. Coach Mike Zimmer says a decision on his availability against the Chargers should be made well before the game Sunday.

The Vikings can ill afford another injury on an already banged-up offensive line. Starting center John Sullivan is out for at least two months after having back surgery, and right tackle Phil Loadholt was lost for the year in the preseason with a ruptured Achilles tendon.

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Defensive tackle Shamar Stephen is the only other Vikings player listed on the injury report. He is probable with a knee injury.