SAN FRANCISCO -- Eliezer Alfonzo may be eligible to return to the Rockies after Major League Baseball recently overturned his 100-game suspension, but Colorado already has a contributor at the backup catcher position.

Wilin Rosario, 23, has been on a home run tear of late, as Monday night's moon shot was his fourth homer in his past 22 at-bats. In all, Rosario is batting .236 with five homers and 11 RBIs in 19 games this season.

"I know sometimes when I get my pitch I can hit it far," Rosario said. "Most of the time when I go to the plate to hit, I'm not thinking about hitting a home run. I'm only thinking to take a quality at-bat every time I go up there."

Rosario's solo blast Monday night went deep into the left-field bleachers at AT&T Park, but he said his first homer of the year in Houston on April 8 traveled farther. The Dominican backstop appeared in 16 games as a September callup last year, batting .204 with three home runs and eight RBIs, but he has been a steady presence behind veteran Ramon Hernandez.

Rosario has also been on the receiving end of Christian Friedrich's initial pair of Major League starts, helping guide the young southpaw to a 1.38 ERA through 13 innings of work. There's still much to learn, though, as evidenced by the communication problems between the tandem last night with runners on base.

As Rosario has settled into his regular role, Hernandez has proven to be a valuable source of knowledge and insight.

"We talk every day," Rosario said. "He's played 13 years in the Majors; he knows how to play this game. He also knows what I have to do to get better every day."

Tulowitzki back in action after foul-ball injury

SAN FRANCISCO -- The Rockies breathed a collective sigh of relief Tuesday after Troy Tulowitzki was inserted back into the starting lineup following Monday night's injury scare. The franchise shortstop was hit in the leg by a Dexter Fowler foul ball as he stood on the top step of the visitor's dugout in the series opener and eventually left the game.

On Tuesday, Tulowitzki was moving around the clubhouse much better even though his knee was heavily wrapped. After taking a 20-minute batting-practice session, Tulowitzki was given the green light to return to the field. But you might not be seeing him waiting in his usual spot before heading to the on-deck circle.

"Maybe not the top, top step," Tulowitzki said. "It's just sore. It's like getting hit by a pitch but on my knee."

Colorado manager Jim Tracy said the ball could have easily shattered Tulowitzki's kneecap and sidelined him for an extended period of time had it landed about three inches higher on his leg.

"We dodged a serious bullet," Tracy said.

That wasn't the only notable roster decision made Tuesday, as right-handed reliever Carlos Torres was optioned down to Triple-A Colorado Springs to make room for Jeremy Guthrie (shoulder), who was activated from the 15-day disabled list.

"[Torres] will start, absolutely," Tracy said. "We want him to pitch some more innings. We're sending Carlos Torres back to Colorado Springs to make room for Jeremy Guthrie. We're not sending Carlos Torres to Colorado Springs because he's done anything that warrants him having to go back down and I made that very clear to the player."

Tracy raves about Friedrich's dominant starts

SAN FRANCISCO -- Manager Jim Tracy could hardly contain himself when reflecting on the week-long Major League career of rookie southpaw Christian Friedrich. Less than 24 hours after seeing Friedrich notch 10 strikeouts and allow one run in seven strong innings of work, Tracy characterized the rookie's initial two big league starts as "dominant."

"The kid that pitched last night, he's making quite a loud statement for himself," Tracy said.

The Rockies skipper has been following Friedrich's career since 2009, Tracy's first year at the helm of the team and Friedrich's first full season with the organization. Tracy said Friedrich has made immense mental strides since the Rockies selected him with the No. 25 overall pick in 2008.

"I basically met two different guys," Tracy said. "There's this guy that looks like he has a chance to do some real special stuff here. Then there's the other guy that wasn't ready to do anything and didn't look like a No. 1 Draft choice. ... He's got it all now and he deserves a hell of a lot of credit."

Friedrich showed plenty of moxie Monday night, controlling the tempo of the game by working fast and mixing up his pitches well. The 24-year-old lefty led off the top of the seventh inning at the plate and Tracy said he didn't hesitate to keep the pitcher in the game. At that point, Friedrich had thrown just 83 pitches.

"You want him to be a finisher," Tracy said. "So you send him back out there and you know the game's hanging in the balance. ... Really encouraged by this kid."