Culberson sent down to make room for Chatwood

SAN FRANCISCO -- The Rockies' evolving roster made another turn when the club optioned utility man Charlie Culberson to Triple-A Colorado Springs to make room for Sunday afternoon's starting pitcher, righty Tyler Chatwood, who was activated from the disabled list.

The Rockies have gone back and forth between 12 and 13 pitchers several times already and went back to 13 with Chatwood healthy after missing two starts because of a left hamstring injury. The move leaves Josh Rutledge, who came up Wednesday and has gone 4-for-5 in two games, as the lone infield backup.

The Rockies finished a three-game set with the Giants on Sunday and will be heading to San Diego for four games starting Monday. They prefer 12 pitchers during road trips, but bullpen usage in the three games going into Sunday was heavy.

That leaves Culberson (2-for-18 in nine games, two starts) the odd man out.

"Our roster is going to be real fluid," Rockies manager Walt Weiss said. "We'll use opportunities to protect our pitching and other times to protect our outfield, protect our infield, and at times send a guy out to get at-bats and stay sharp. If a guy isn't getting everyday at-bats up here, there's going to come a time to send him down to Triple-A so he can stay sharp. They can be sharp when we bring them back."

One reason for having Rutledge and Culberson was shortstop Troy Tulowitzki was battling right quadriceps tightness for the past week. But, Weiss said, "Tulo got through the worst part of it and seems to be doing much better. I feel comfortable where we're at."