DENVER -- Back in town after a stint as rehabbing star, mentor and storyteller in the Minors, Rockies first baseman Jason Giambi said Saturday he is refreshed for the final month of the season.

Giambi, 41, had missed 35 games with what is being called viral syndrome, which Giambi said he would explain at a later date. On Saturday, he said his focus was on a strong finish in whatever playing time is available to him on a squad that has turned young in his absence.

"Just go play and show that I can still play," Giambi said. "I hit the ball well while I was down there. I was swinging the bat good before I got sick. I'm excited to be back with the guys. They're playing some good baseball. I'm glad to be a part of it."

Giambi made an immediate impact upon his return on Saturday night, hitting a pinch-hit single in the eighth inning against the Padres before Dexter Fowler's grand slam that made it 9-1.

Giambi is back after five injury rehab appearances -- three at Double-A Tulsa and two at Triple-A Colorado Springs -- during which he hit .385 (5-for-13) with a double. Giambi said he relished the time at Tulsa, where many of the players were not much more than half his age.

"They wanted to hear all of the stories," Giambi said. "It was fun. It was fun to see them grind down there, to watch them play.

"My energy level is back. I feel great. I played some first base. Whatever they want me to do here is fine with me. I know they're taking a lot of long looks at a lot of these guys."

Giambi said he hopes to pass on the game to younger players, the way current Rockies hitting coach Carney Lansford, Mark McGwire and Terry Steinbach did for him when he broke in with the Athletics in the mid 1990s.

But Giambi wants to keep playing, as well. The opportunity might not be in Colorado, where he has been since late in the 2009 season, but he expects to be in uniform again in 2013.

"I would love to play if I can get a job, but that's kind of up to everybody else," said Giambi, who was hitting .241 with four doubles, a home run and eight RBIs in 47 games before going to the disabled list.

Moscoso called up from Colorado Springs

DENVER -- The Rockies recalled right-hander Guillermo Moscoso from Triple-A Colorado Springs on Saturday. He and first baseman Jason Giambi were the only players added to the roster on the first day that Major League teams were allowed to expand rosters up to the limit of 40.

Moscoso, 29, obtained in a trade with the Athletics during the offseason, is 0-1 with a 7.53 ERA in 13 games, including three starts, during his three previous stints with the Rockies. At Colorado Springs, he went 8-6 with a 6.13 ERA in 18 starts.

Moscoso will be used out of the bullpen, although manager Jim Tracy said it's possible Moscoso could be used as a hybrid -- up to 50 pitches a game, behind the starter -- the way Josh Roenicke, Carlos Torres and Adam Ottavino are being employed.

Worth noting

• Shortstop Troy Tulowitzki returned to the Rockies for an evaluation after playing seven innings for Triple-A Colorado Springs on Friday night. Tulowitzki, who had surgery to remove scar tissue from his left groin in June, has played six games, three each at Double-A Tulsa and Colorado Springs.

The Rockies can activate Tulowitzki at any time, but it's not clear if Tulowitzki is exactly where he needs to be.

"It's just a matter of picking the right time," Tulowitzki said Saturday. "I still haven't been tested on the bases, but I feel good at the plate. I'm getting there."

• Left-hander Jorge De La Rosa, who last pitched in May, 2011, before undergoing Tommy John surgery on his elbow, faced hitters at Coors Field on Saturday. The Rockies have been hoping he can pitch before the season is done. The club will evaluate him on Sunday before taking the next step.