DENVER -- The 2012 season has seen the Rockies' rotation deal with its fair share of turmoil. For a brief glimpse, look no further than the upcoming series in San Diego, where only one of three starters for the Rockies has been announced, and two of the starters may not even be on the roster.

"This is the toughest I've had to deal with," manager Jim Tracy said Sunday regarding the uncertainty surrounding his rotation. "And yet I give everyone here a ton of credit. We still find ways to come out here and battle every day."

Opening Day starter Jeremy Guthrie, on the disabled list with a banged-up shoulder from a bike accident a week ago Friday, threw a second bullpen session Sunday and came out of it with no issues.

"It went great," Guthrie said. "Roughly 45 pitches. I was able to throw all my pitches to all the locations without any pain. It was more letting it go and feeling normal. Don't quote me on exactly what will happen Tuesday, but I'll definitely be throwing in some way shape or form, whether it's an extended bullpen or to hitters."

Throwing to hitters is the ideal next step for Guthrie, setting him up for a subsequent decision about whether he's ready to return to the Majors or if he needs a brief a rehab assignment in the Minors.

"He's not going to throw to hitters until we pass the bullpen test where we're eliminating language using the terms 'tentative,' 'didn't completely feel just right,' or 'just kind of felt it on a couple pitches,'" Tracy said before Guthrie's bullpen session Sunday. "We have to pass this test first, and then we have to throw live batting practice, and quite frankly for me, we're getting very close to the point where we may have to make a rehab start before we just run out here to the big league mound."

Tracy is adamant about not being put in a position of sending a starter to the mound and having to pull him after two innings when something doesn't feel right. His bullpen has met the challenges of often throwing more innings than the starters, but the pattern cannot continue.

"There has to be a turnaround there," Tracy said. "We're still searching, there's no getting around that."

Among those who might help are Josh Outman, who threw 36 pitches (25 for strikes) over two innings in his rehab assignment in Double-A Tulsa on Thursday and was slated to throw in back-to-back games Sunday and Monday.

Outman could be a candidate to join the club if all goes well with his outings, and depending on how things shake out over the next few days at the Major League level. Outman would be a fresh left-handed relief arm, potentially spelling some of the inconsistency that plagued the 'pen on the homestand.

Carlos Torres pitched his first inning for the Rockies on Saturday night, putting down the Braves on nine pitches in the eighth, and he pitched a perfect ninth Sunday on 12 pitches. He was recalled from Triple-A on Friday to be available for long relief and potentially to take a start next week.

"He's a candidate to start a game," Tracy said. "He's also a candidate to stay and pitch and be that long man/spot starter type of guy and give us a chance to see more of his stuff. Over the course of the next 72 hours, there's going to be some decisions made."

The Rockies are also considering calling up Christian Friedrich or Alex White from Colorado Springs. Friedrich is scheduled to pitch Wednesday in Colorado Springs, and he has been the most effective starter there, but he is recovering from a hamstring injury and is still lengthening out. White was scheduled to pitch Sunday, but was scratched to keep him available to the Rockies.

Tulo, Tracy not concerned about defense

DENVER -- When the Rockies went to the World Series in 2007, they did so in part on the strength of a record-breaking defense that established a rock-solid foundation for all aspects of their game.

Early in 2012, they find themselves at the other end of the spectrum, with their 24 errors the second highest in the league. On Saturday night, they made a season-high four errors in a 12-9 loss to the Braves, with Gold Glovers Troy Tulowitzki and Carlos Gonzalez committing errors in the same inning for the second time this season.

"I think just like with hitting, it's contagious a little bit, defense," Tulowitzki said. "You start to get one, two, and guys start to think about it a little bit. But we're a better defensive team than we've shown. We've just kind of struggled early. There's no real excuse. The weather hasn't helped sometimes. When bad weather's come, we maybe got a little tight or whatever, but there's really no excuse for it."

Tyler Colvin's error in center came when he put enough effort in to track down a ball at the warning track with his back to the plate, but watched it bounce off his glove. Gonzalez's ball was lost in the lights, and Esmil Rogers' throwing error in a pickoff attempt at second was a mental lapse that found him throwing to an empty base while the infield was positioned to defend against a bunt. Tulowitzki's miscue came on a routine grounder by the pitcher, Mike Minor, and he still isn't sure how he missed the ball.

"I wish I had an answer," Tulowitzki said. "I missed it. I couldn't believe it when it happened. Maybe I took my eye off it a little bit early. I don't know. Believe me, it bothers me big time, but there's nothing you can do about it."

Despite the uncharacteristic defensive lapses, neither Tulowitzki nor manager Jim Tracy are concerned about an ongoing issue.

"Was last night sloppy?" Tracy asked. "Yes it was. But over the long haul through the 26 games we played, have there been moments of brilliance in the 26 games? I think there has or we'd have no chance at being 12-14. It's a big old deep hole that we [would] get into that we [would] have to climb out of."