SAN DIEGO -- It's been a tough year for Padres starter Tim Stauffer. The 30-year-old righty was scheduled to be the Opening Day starter before being the first of the long line of San Diego starters to land on the disabled list.

And while Stauffer looked poised to return in time for at least a handful of 2012 starts, a setback during last week's rehab stint may force him to look toward 2013 rather than push for a late-season return.

Originally on the DL with right elbow soreness, Stauffer was scheduled to make a second rehab start with Triple-A Tucson on Thursday and appeared to be on the precipice of a Major League return. But during some between-start work earlier this week (Stauffer pitched three innings in Tucson last Saturday), he felt soreness in his pitching shoulder and was sent back to San Diego.

"He's not feeling well," Padres manager Bud Black said. "His shoulder acted up a little bit; his elbow's still a little bit sore. ... There's no doubt this is a setback for him."

This would be the second failed comeback attempt for Stauffer, who made it all the way back to the big leagues in May, only to be placed right back on the DL after the soreness returned in a May 14 start against the Nationals.

Given that he threw 185 2/3 innings, struck out 128 and pitched to a 3.73 ERA in 2011, and considering how close he's come to reclaiming that major role in the San Diego rotation this year, it's not surprising that Stauffer and the Padres are frustrated to have another comeback attempt stymied by lingering injury.

"For Tim and all of us, it's been a frustrating year healthwise," Black said. "He tried to ramp it back up, worked awful hard to try to get in a position to go out on rehab, and there's something physically wrong, and it's a bummer, it really is."

"It might be [a situation where we shut him down for the year]. ... We're going to exhaust all the medical opinions ... do everything we can for Tim to make sure the road we take is the right one," Black added. "This is a tough one based on what time of the year it is and the couple times he's tried to come back and it hasn't worked out."

Grandal comes off DL, gets right to work

SAN DIEGO -- The Padres activated rookie catcher Yasmani Grandal from the disabled list Friday and didn't waste any time getting him back in the lineup. Grandal, who was placed on the disabled list July 31 after straining his right oblique on a swing in Cincinnati, started behind the plate and hit fifth in Friday night's series opener against Matt Cain and the Giants.

Grandal caught his first game since the injury Thursday night in Lake Elsinore, Calif., as the Class A Storm dropped a 6-3 decision to the Inland Empire 66ers. He was 0-for-3 in the game, but did throw out a runner trying to steal second.

That was just the second day of in-game action for the 23-year-old, who DHed in the Storm's Wednesday night game. And while he was 0-for-4 in that game -- and therefore hitless in his rehab stint -- Grandal isn't reading too much into those results.

"The result for me wasn't the priority; the timing, getting in the game, having situations was the main thing for me," Grandal said. "One of the reasons I went down is to get a couple of in-game swings because it's a different swing. ... During [batting practice], you might go 60, 50 percent just so that you don't redo it again. ... It seems like it's back to normal."

The Padres certainly hope that's the case, as Grandal was hitting .312 with five homers and 15 RBIs in 24 games in two big league stints this season. He burst into the San Diego lineup when he homered from both sides of the plate in his first Major League start June 30 in Colorado.

Since then, he's been an important cog in the center of the Padres' lineup, and manager Bud Black is very happy to see him back in there.

"It's big. ... It's good to have him back," Black said. "I think our lineup looks a lot better when he's in the middle of it. He plays with a lot of energy, young guy trying to make his mark. ... We're excited."

Grandal's place on the 25-man roster was cleared by moving catcher Nick Hundley to the 15-day DL with a right knee contusion.

Short hops

• Hundley was placed on the 15-day DL on Friday with a right knee contusion and irritation. According to Black, Hundley had been feeling something for about three weeks, and an MRI revealed "irritation."

Hundley was recalled to the Padres on Aug. 9 after spending all of July with Triple-A Tucson to reverse the offensive struggles that plagued him during the first few months of the season. Hundley is hitting .157 in 58 big league games this year, but was leading the Majors in runners caught stealing when he was sent down June 30.

• Pitchers Anthony Bass (right shoulder) and Andrew Cashner (right lat) are both making progress in their rehab. Both hurlers threw simulated games at the Padres' facility in Peoria, Ariz., on Friday, and Black said they may be ready for rehab appearances with Triple-A Tucson pending the outcome of those sessions.

• Closer Huston Street, who was placed on the 15-day DL with a left calf strain Aug. 11, is still limping heavily and struggling to walk. Black said that as of Friday, there was no specific timetable for his All-Star closer's return, but that he expects him to be out longer than just the required 15 days.

"This is not going to be 15 days; he's not pitching on the 16th day," Black said. "This is a calf strain. ... It's legit."