LOS ANGELES -- The idea that outfielder Tyler Colvin is strictly a backup for the Rockies could be changing.

Colvin started in center field, instead of Dexter Fowler, on Saturday against the Dodgers, and manager Jim Tracy said Colvin -- hitting .314 with two home runs and 10 RBIs -- has earned greater opportunity to start.

The Rockies aren't going away from left fielder Carlos Gonzalez, who leads the team in home runs (seven) and RBIs (26), or right fielder Michael Cuddyer, who is hitting .286 with four homers and is tied with first baseman Todd Helton for second in RBIs with 21.

That means Colvin's starts will come at the expense of Fowler, who is hitting .223 with four homers and 14 RBIs.

"In any given situation he's made the most of it, whether it's starting a game, coming off the bench," Tracy said. "We've gotten quality at-bats from him as a starter. He's done a terrific job as a left-handed pinch-hitter.

"You've got to get him out there tonight. He's pushing the envelope for more time. When a player does that, you have to be mindful of it and create additional opportunities for him to play. He is making a strong statement for himself to get more at-bats than he's gotten to this point. We're doing what's in his best interest and also our baseball team's best interest in getting him additional opportunities."

Colvin and Triple-A infielder DJ LeMahieu joined the Rockies in a Dec. 16 deal with the Cubs, for third baseman Ian Stewart and right-handed relief pitcher Casey Weathers.

At this early stage it appears the Rockies are getting the better of the deal. Stewart is hitting .183 with three home runs and 11 RBIs in 109 at-bats as the regular third baseman. Weathers was removed from the Cubs' Major League roster during the spring.

Fowler has a .311 on-base percentage and 27 strikeouts in 94 at-bats and has had two errors and a couple of defensive miscues. Colvin has an outfield error and 19 strikeouts in 51 at-bats.

One reason for the change Saturday is the Rockies have a .226 road batting average as a team and need production. Fowler entered Saturday night 2-for-11 this road trip. Colvin was 3-for-7.

De La Rosa bothered by forearm in rehab start

LOS ANGELES -- Rockies left-hander Jorge De La Rosa was removed after one inning of his injury rehab start Saturday night at Double-A Tulsa as a precaution because of forearm tightness, the Tulsa World newspaper reported via Twitter on Saturday night.

De La Rosa, returning from Tommy John surgery on his left elbow last year, had made two starts at Class A Modesto. On Saturday against Arkansas, he gave up five hits and four runs while throwing 28 first-inning pitches, then was seen talking with a trainer. He did not go out for the second inning.

It is not clear if this will lengthen the injury rehab assignment. Pitchers have a 30-day window, but any new injury could allow the team to restart the window. When manager Jim Tracy announced the beginning of De La Rosa's rehab assignment, he emphasized that there would be no time clock and De La Rosa will be activated only when ready.

De La Rosa, 31, was the Rockies' best pitcher last year (5-2, 3.51 ERA in 10 starts) when he suffered the torn elbow ligament in May during a start at home against the D-backs. De La Rosa is at the back end of a two-year, $21.5 million contract that also has a player option for 2013 that is worth $11 million.

Rested and ready, Outman joins Rox bullpen

LOS ANGELES -- The Rockies need left-handed relief pitcher Josh Outman to help a tired bullpen.

Outman no doubt needs the Rockies to help put behind him a story that he can't enjoy telling.

The Rockies activated Outman, 27, on Friday and he joined the club for Saturday night's game against the Dodgers. Outman began the year on the disabled list with a strained right oblique muscle. He suffered the injury not long after being informed late in Spring Training that he had made the team. He was battling food poisoning and suffered the injury from the force of his vomiting.

Outman rested and strengthened for two weeks, went on a gradual throwing program and didn't give up a run and struck out seven in seven innings over six Minor League rehab outings.

"There were a few clever puns made that I was the butt of, but in all reality there are a lot worse things that could've happened," Outman said. "I don't really like going to the hospital. I don't think anybody does. But my wife asked if I needed to go in and I said, 'Yes, immediately.'

"I was at the point of dehydration that my skin was pruning. I had no water left in me at all. It took three bags of fluid before they discharged me. I think it was just the force of [vomiting] and the repetition."

Outman went 8-8 with a 3.75 ERA as a starter and a reliever with the A's from 2008-11. He came to camp as a competitor for a rotation spot but suffered from biceps tendinitis early in camp and showed promise as a reliever when he became healthy.

Rockies manager Jim Tracy said Outman can pitch in a longer role or as a lefty specialist. Also, Tracy said he might need Outman to work in the seventh or eighth inning, because primary lefty setup man Rex Brothers has had inconsistent command.

"He's had a couple of days off, so not only is he with us, but he's ready and available for whatever it is that presents itself," Tracy said.

Outman said the rehab program has made him strong.

"They had a few things they wanted me to prove to them and prove to myself -- be able to go a couple of innings, throw back-to-back [games]," Outman said. "I was also able to work on some things mechanically. There are things that you can tinker with as the season rolls on, but I try to look at the positives -- what few there were in this situation."

Worth noting

• Pinch-hitter and backup first baseman Jason Giambi fouled a pitch off his right foot during Wednesday afternoon's victory over the Padres and is still sore. Rockies manager Jim Tracy said he was not sure whether Giambi would be available Saturday night. The Rockies also usually rest regular first baseman Todd Helton for day games after night games. If Giambi cannot go Sunday, Tyler Colvin and Michael Cuddyer have experience at first base.