The St. Louis Rams continue to monitor their three key starters who left last week's game against the Chicago Bears with a concussion as they move toward Sunday's game against the San Francisco 49ers.

Running back Zac Stacy, cornerback Trumaine Johnson and left guard Chris Williams did not participate in Wednesday's practice according to the team's official injury report, but all three are making strides in a positive direction according to coach Jeff Fisher.

"All three of them are doing well," Fisher said. "They're all going through the process right now and they're all doing well."

Stacy and Johnson, in particular, appeared to be in pretty good shape Wednesday. That duo spent part of the practice running sprints on the side with head athletic trainer Reggie Scott.

Toward the end of Wednesday's practice, the Rams removed their pads and went to a walkthrough pace. All three players participated at the walkthrough pace.