Starting right guard Chris Villarrial did not practice Wednesday because of a right ankle injury and is expected to miss this weekend's game at Chicago.

Villarrial was listed as doubtful, and coach Dick Jauron said he will need at least a week of rest. Jauron said tests revealed the injury was to a tendon in Villarrial's ankle, and not a high ankle sprain as initially feared.

Villarrial was hurt in the second quarter of Buffalo's 17-12 win over Minnesota last weekend, when he opened a hole for Willis McGahee at the Vikings' goal line. As Villarrial fell into the end zone, several players fell on the back of his leg.

He stayed in for the next play, when McGahee scored from the 1, but the lineman missed the rest of the game and was spotted leaving the stadium wearing a protective boot.

Duke Preston will take over at guard, making his second career start.