The injuries keep piling up for No. 4 Baylor, which lost another starter Tuesday when the school confirmed offensive lineman Spencer Drango is having back surgery.

The sophomore left tackle had started 22 games in a row for the Bears and is considered one of their best linemen alongside All-America left guard Cyril Richardson. He’d been dealing with back issues for a while, and the last straw came in Baylor’s 66-34 win over Texas Tech.

His replacement is expected to be Pat Colbert, a 6-foot-5, 305-pound sophomore who has appeared in Baylor’s last 22 games, but has never started. How long Drango will be sidelined remains unknown, but don’t expect him on the field when Baylor takes on No. 10 Oklahoma State this weekend in Stillwater, Okla.

Drango is the latest in a recent rash of injuries that has tested Baylor’s depth. Second-leading receiver Tevin Reese is done for the season. Running backs Lache Seastrunk and Glasco Martin are both questionable for the OSU game after missing last week. And the Bears don’t know whether they’ll have starting linebacker Bryce Hager on the field after he left the Texas Tech game with a groin injury.

Losing Drango could mean more pressure for Baylor quarterback Bryce Petty, though Oklahoma State is in the middle of the pack in the Big 12 when it comes to sacks, with 20 on the year and 13 in Big 12 play.

But Baylor's offensive line has also made life easy for the Bears’ collection of running backs. Third- and fourth-string backs Shock Linwood and Devin Chafin each rushed for 100 yards against Texas Tech, and both credited the big guys up front for that feat.

Oklahoma State has injury problems of its own, none bigger than the questionable status of receiver Josh Stewart. But Drango is a potentially a critical loss, the kind Baylor can’t have too many more of in its quest to win the Big 12 and play for a national championship.