DENVER -- Matt Reynolds has a simple way of rationalizing his outing on Saturday night against the D-backs, amounting to the first win of his big league career.

"It was awesome," he said. "Better than my first big league loss."

Fair enough. The southpaw has shown great promise out of the bullpen since debuting Aug. 19, working his way to a 1-0 record and 2.53 ERA. Before allowing his first big league runs Sept. 2, the rookie allowed just two hits in his first 6 2/3 innings.

Most importantly, though, Reynolds has been critical in helping shoulder some of the load that the beleaguered 'pen has endured this season.

"The more rope I gave him, the more he kept pulling out of my hand," Rockies manager Jim Tracy said. "And that's what I'm looking for. ... He's added length to what we can do now."

Tracy admitted he wouldn't use Reynolds in a variety of situations when the youngster joined the club. But over time, Reynolds has accepted the challenge and has since been inserted into a variety of roles.

"It's kind of a process," Reynolds said. "You've got to earn your spot. I don't know if I've earned it yet, but I feel like I'm working toward trying to earn it every time I take the mound."

Iannetta day-to-day with right calf strain

DENVER -- Catcher Chris Iannetta came out in the second inning of Colorado's 4-2 win against the D-backs on Sunday with a right calf strain.

"He did it on the double-play ground ball that Chris Young hit in the first inning," Rockies manager Jim Tracy said. "He came back to catch and [assistant athletic trainer Scott Gehret] noticed he was doing a lot of different things with his foot and stuff like that, like it was he was cramped or something like that. When he came in, he said he felt something that didn't feel good at all."

Miguel Olivo replaced Iannetta in the top of the second and hit in Iannetta's place in the order that inning, striking out. Olivo went 0-for-3 with a walk and scored the tying run on Ryan Spilborgh's bloop double in the seventh.

Iannetta, hitting .210 with nine homers and 25 RBIs this year, is five for his last 17 with two homers and five RBIs. He is considered day-to-day.

"I was jogging and the first few steps, it kind of tightened up on me," Iannetta said. "I wasn't sure if it was a cramp or I tweaked it. So we'll find out probably the next couple days. It's sore, nothing major. I'll probably just need a few days to rest."

Olivo rediscovering offensive groove

DENVER -- Miguel Olivo has felt it building for weeks, trying to work out of a second-half slump. He's put an exclamation point on it this weekend.

The Rockies catcher, who smacked a bases-clearing triple into the left-field gap Friday and has six RBIs in his last five starts, appears to be finding his groove again at Coors Field.

"I'm hitting the ball better," said Olivo. "I know there were months that killed me. That's baseball. You have some days where you're not good and other days when you're up again. I'm getting myself together and I'm hitting the ball better."

Nearly an All-Star selection this year, Olivo hit .325 with 11 homers and 42 RBIs before the break. Since, he's hit just .202 with two homers and 14 RBIs. But he's come along in the last few weeks, with a hit in each of his last six starts.

He's hitting .417 (10-for-24) with four doubles and a triple in that span. He also recorded the game-tying RBI single in the seventh inning of Saturday's 2-1 win against the D-backs.

"In August, I was thinking too much about home runs and I opened up a lot," Olivo said. "But now, I'm not trying to think about home runs. I'm trying to put the ball in play and hit the ball to right field. That's why my swing is better right now."

Tracy likes what he sees from Smith

DENVER -- As Jim Tracy continues to plug Seth Smith into the starting lineup, Colorado's manager is hoping the outfielder will continue to grow into the offensive player he expects him to be.

Tracy feels that Smith, hitting .258 entering Sunday's series finale against the D-backs, can be a .300 hitter who can spray the ball to all fields.

"The biggest thing with Smitty is staying through the ball," Tracy said. "When you come off, you go from hitting the ball right in the sweet spot of the barrel to coming up toward the end."

A huge key for Smith's consistency comes in hitting against left-handers. He's batting .278 against righties, but just .154 against southpaws entering Sunday.

Twelve of Smith's last 19 hits have gone for extra bases, and the lefty has hit all 17 of his homers off righties. He proved he can hit for average from June through September last season, when he hit .305 -- a feat Tracy is confident could be repeated.

"I was extremely encouraged the other night when he had a line-drive out and also hit a line-drive single toward center," Tracy said. "That's all he has to do. And in between some of those pitches that show up, just don't hit through the ball. He's got power everywhere."

Worth noting

Third baseman Ian Stewart continues to receive treatment with hopes of returning early this week from a strained oblique. ... Closer Huston Street's nine straight saves is the third-longest active streak in the National League. ... Entering Sunday, the Rockies are 9-2 in September and hold the NL's best record (57-33) in the month since 2007. Only the Yankees (60-31) have a better mark.