DENVER — The St. Louis Cardinals could be getting a key piece of their lineup back just in time for September's stretch run.

On Friday, Masyn Winn took batting practice at Coors Field, the final hurdle in his return after being out since August 25 with a left thumb fracture. Winn injured his thumb on August 18 sliding into second base against the Cincinnati Reds.

"He took swings off a machine full speed yesterday (Thursday) and felt good," Cardinals manager Oliver Marmol said before the Cardinals opened a three-game weekend series against the Colorado Rockies. "We're going to hit BP today and if he comes out of that feeling good, then he can be active as early as tomorrow."

Marmol said Friday would be the key for Winn's next steps.

"We want to see how he comes in today, hits regular BP, do everything team-related and then go from there," Marmol said.

What Masyn Winn's return to St. Louis Cardinals might mean

In 122 games so far this season, Winn is slashing .238/.314/.326 with five home runs, 19 doubles and 51 RBI. 

JJ Wetherholt has been filling in for the Cardinals at shortstop in Winn's absence, but he landed on the injured list on Sunday with right tendinitis. With both Wetherholt and Winn out, Thomas Saggese has held down shortstop while Jose Fermin or Bryan Torres has been at second base.

That revolving door will lighten upon Winn's return, giving the Cardinals stability at shortstop while they want for Wetherholt to heal and return to second.