SAN FRANCISCO -- Five days after winning his Major League debut, Rockies southpaw Christian Friedrich took the mound against the Giants on Monday night.

Along with righties Juan Nicasio and Alex White, Friedrich helps make up Colorado's promising crop of young arms. But as he watches the young starters try to make their way in the Majors, manager Jim Tracy wants to see evidence of mental development.

"They're all capable enough and qualified enough with the stuff that they have," Tracy said. "I think more so they need to understand that when you create offensive opportunity for the other side, they're going to capitalize."

Grooming young pitching staffs is nothing new to veteran catcher Ramon Hernandez. In fact, it's already been a decade since he was calling games for Oakland's young trio of Tim Hudson, Mark Mulder and Barry Zito.

"The key to being successful is you have to know your own game," Hernandez said. "You got to know what your catcher wants to do and you've got to know what kind of pitcher you are. The sooner you figure that out, the sooner you can make a plan and you'll understand how to pitch."

White also fared well in his Rockies debut last week, but followed it up by giving up six earned runs in 4 1/3 innings during Sunday's 11-5 loss against the Dodgers. Above all, Tracy wants his pitchers to be the aggressors on the mound.

"I'd rather see our younger guys out there as aggressive as a [Matt] Belisle, a [Rafael] Betancourt, some of those guys and say, 'Hey, I'm coming after with the best stuff that I have and if you can put three hits in a row together, you'll produce a run,'" Tracy said. "We're not doing that and we have to do that."

Tracy notes Alfonzo's rescinded suspension

SAN FRANCISCO -- Jim Tracy may be Colorado's skipper, but he found out about Eliezer Alfonzo's overturned suspension just like the rest of the world.

Alfonzo, who played 25 games as a backup catcher last season, had his 100-game suspension lifted by Major League Baseball recently due to similar procedural reasons that affected the case of Milwaukee slugger Ryan Braun. Tracy said he learned about Alfonzo's situation by watching TV Sunday night, after it was first reported by the Associated Press.

"It was pretty intriguing for me sitting there last night and seeing that go across the bottom line," Tracy said.

Alfonzo was not in camp with the Rockies this Spring Training and is currently believed to be in Venezuela, according to reliever Rafael Betancourt. The 33-year-old catcher batted .267 with a home run and nine RBIs in 75 at-bats last year, but Tracy didn't want to speculate on his future with the club until everything is official.

"I'm happy for that young man because he was a model citizen for us last year," Tracy said. "In his own way, he did a nice job of making a contribution and helping us to win a few games last year."

Colvin gets start as Fowler given more rest

SAN FRANCISCO -- The Colorado cleanup spot was once again occupied by Troy Tulowitzki on Monday, a day after he was dropped down to the No. 5 hole in the order. Manager Jim Tracy also kept Tyler Colvin's hot bat in the lineup as the starting center fielder, electing to keep Dexter Fowler on the bench as he recovers from a head injury he suffered after being hit by a throw Sunday.

"[Fowler] was examined by the doctor last night and I was told that he was showing no signs whatsoever of any concussion-type symptoms," Tracy said. "I still want to err on the side of caution with that and give him another day."

That's not to say the center-field position will be Fowler's by default once he returns. Tracy had glowing words for Colvin, the 26-year-old who was acquired via trade from the Cubs this offseason, before Monday's game.

"With the contribution that this young man is making offensively right now, there's any number of days where you're going to have to find a place for this guy to play right now," Tracy said. "That's the long and the short of it."

Colvin has started each of the past three games and four of the past six. Entering play Monday, Colvin was batting .467 (6-for-13) in his previous five games. Fowler, meanwhile, is batting .221 with four homers and 14 RBIs in 31 games this season.

But Tracy said Colvin's value goes beyond his numbers, as he has the ability to play all three outfield positions and first base. Tracy has also been impressed with Colvin's ability to hit lefties and hinted that he will likely start at first base in place of Todd Helton on Wednesday in Arizona.

"He's made some wonderful strides since we acquired him, there's no question about that," Tracy said of Colvin.

Worth noting

• Tracy said right-hander Jhoulys Chacin, on the disabled list with right shoulder inflammation, has not started a throwing program and is currently working on building up strength. For now, there is no timetable for Chacin to begin throwing again. "He'll remain on the program that he's on right now and that's just some rest and strengthening exercises," Tracy said.

• Jason Giambi said his foot was feeling "good" before Monday's game but it was unknown if he would be able to pinch-hit in the series opener against the Giants. Giambi, who suffered a foot injury Wednesday, appeared to take a full round of batting practice and spoke to Tracy shortly after completing his rounds in the cage.