Kansas City, Mo. ? Chiefs quarterback Matt Cassel was limited in practice Thursday and his availability for Sunday’s game at St. Louis remained unclear.

Cassel underwent an emergency appendectomy Dec. 8. He missed last week’s game at San Diego, a 31-0 loss that trimmed the Chiefs’ lead over the Chargers to one game in the AFC West. The lead now is one-half game. K.C. coach Todd Haley says Cassel and backup Brodie Croyle were both being prepared as possible starters against the Rams.