DENVER -- Michael Cuddyer strained his left hamstring on April 17 in what turned out to be a 3-1 win at San Diego that left the Rockies with an 8-9 record. He was placed on the 15-day disabled list April 21 and from that date until the start of play Tuesday, the Rockies went 15-10. Nonetheless, having Cuddyer -- the reigning National League batting champion -- return, figures to help the Rockies.

"He's been out about a month, so getting him back is a big deal," Rockies manager Walt Weiss said. "Anytime our lineup has him in it, we're a better club."

Cuddyer's primary position is right field, but he played first base Tuesday against the San Francisco Giants in place of left-handed hitting Justin Morneau against San Francisco left-hander Madison Bumgarner.

"Feels good to be able to get back on the field," Cuddyer said. "Put my pom-poms away and pick up a glove instead. That's nice."

Cuddyer went 0-for-4 with a walk and two strikeouts. But Morneau pinch hit in the ninth and drew a walk to start a rally that culminated with a two-out, two-run walk-off double by Nolan Arenado that gave the Rockies a 5-4 win.

To make room on the roster for Cuddyer, the Rockies optioned reliever Chris Martin to Triple-A Colorado Springs. Those moves left the Rockies with six outfielders and 12 pitchers. The Rockies have gone from 12 pitchers to 13 and back often this season. They prefer to have the extra hitter for a three-game series with San Francisco that started Tuesday and a nine-game road trip that begins Friday in Atlanta and includes stops in Philadelphia and Cleveland.

Martin, who began the season at Colorado Springs, made his major league debut April 26 and in nine games for the Rockies had 4.15 ERA with two walks, eight strikeouts and 10 hits allowed in 8 2/3 innings. Veteran Nick Masset, who joined the Rockies on May 5 and is 1-0 with a 1.50 ERA in six games supplanted Martin, giving the Rockies an experienced right-hander to protect leads.

Weiss said, "Typically, when we're getting ready to go on the road, we'll go with 12 pitchers. We had to make a move with 'Cuddy.' and that seemed like the thing to do. We'll go back to 13 at some point. Chris Martin is a big part of hise club. He's pitched very well for our bullpen. He'll be back."