ORCHARD PARK, N.Y. (AP) -- Buffalo fullback Darian Barnes will have tests on his injured right foot Monday, leaving his status uncertain for the Bills' game at St. Louis on Sunday.

Coach Dick Jauron didn't discuss the nature of the injury, except to say Barnes will have tests later in the day.

Barnes was hurt when he tumbled awkwardly into the sideline after a nine-yard reception midway through the second quarter of Buffalo's 24-23 win against Oakland on Sunday.

Barnes got up favouring his right leg, but stayed in the game for a few plays before limping off the field and did not return.

Barnes was spotted after the game wearing a protective boot on his right foot. He was not in the locker room Monday, but there was a pair of crutches leaning against his stall.

The Bills, with their first 3-0 start since 1992, are off until they return to practice Wednesday.

A seven-year NFL veteran, Barnes signed with the Bills this off-season after first-year offensive co-ordinator Turk Schonert re-introduced the fullback position.

Tight end Derek Schouman filled in at fullback after Barnes was hurt.