PITTSFORD, N.Y. — Buffalo Bills starting left tackle Cordy Glenn took the next step in addressing lingering soreness in his left foot by receiving an injection.

In announcing Tuesday that Glenn was listed as week to week, coach Sean McDermott said only that the player travelled to Wisconsin to have the procedure done by foot specialist Robert Anderson. McDermott would not disclose the nature of the injury or the injection, which took place a little more than a week after Glenn was examined by Anderson .

"The doctors are hopeful. We're all hopeful," McDermott said. "We're hopeful at this point that this is something that finalizes it and knocks it out and Cordy can return on a full-time basis."

Glenn has been in and out of a walking boot for much of the off-season, and missed the team's entire series of spring practices. He was cleared for the start of training camp before missing five of the past eight practices as well as a preseason-opening 17-10 loss to Minnesota on Thursday.

McDermott has previously not ruled out the possibility of Glenn requiring surgery. On Monday, he said the team will have to develop a contingency plan in the event the issue lingers.

Glenn has been the Bills' starter since being selected in the second round of the 2012 draft. He is also the team's top paid offensive lineman after signing a five-year, $65 million contract extension last year.

Buffalo already lacks experienced depth at tackle, with backup Seantrel Henderson set to miss the first five games as he finishes serving his 10-game suspension for violating the NFL's substance abuse policy. Michael Ola and rookie third-round draft pick Dion Dawkins are next in line as potential starters.

Aside from Glenn, McDermott also ruled out receivers Jordan Matthews (chest) and Jeremy Butler (concussion) and safety Bacarri Rambo (hamstring) from playing in Buffalo's preseason game at Philadelphia on Thursday.

Ola (left toe), cornerbacks Shareece Wright (sprained thumb) and Kevon Seymour (foot) and defensive tackle Adolphus Washington (back spasms) are considered questionable to play.

Rookie quarterback Nathan Peterman has moved ahead of T.J. Yates in being named the primary backup to starter Tyrod Taylor for Thursday's game. Peterman has been practicing with the second-team offence since Sunday, and after going 13 of 25 for 112 yards and a touchdown against Minnesota.

The Bills held their final practice at training camp and will begin working at their headquarters in Orchard Park starting Friday.

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