PITTSBURGH — Pittsburgh Pirates opening day starter Oliver Perez was demoted to Triple-A Indianapolis on Thursday, the club's latest move to try to turn around the hard-throwing pitcher once seen as their staff ace.

Perez has struggled with his control, mechanics and velocity for a second consecutive season, going 2-10 with a 6.63 ERA in 15 games. He and Jorge Sosa of the Braves are tied for the NL lead in losses.

"We hope that by making a series of starts down there, he can regain his consistency," manager Jim Tracy said. "We hope he can relax and have the opportunity to think through a lot of the things that we've been working on with him."

To replace Perez on their 25-man roster, the Pirates recalled left-hander Tom Gorzelanny and will start him Saturday night against Detroit.

The 23-year-old Gorzelanny, a second-round draft pick in 2003, was 6-5 with a 2.35 ERA in Triple-A after going 0-1 in three games with Pittsburgh late last season.

Gorzelanny is the third left-hander to be recalled and move into the Pirates' rotation in the last two seasons, joining Zach Duke and Paul Maholm.

Perez was told earlier in the week he was being demoted to the bullpen, but made no relief appearances before being sent down. He hasn't pitched in the minors since appearing in eight Triple-A games for San Diego in 2003, before being traded with Jason Bay to the Pirates in the Brian Giles deal.

Perez almost seemed resigned to returning to the minors, perhaps because he appeared to be one more bad start away from being sent down earlier this season.

"Maybe I can go down there and relax," Perez said. "Up here, I would walk somebody and then start thinking too much."

After starting the season 1-5, Perez made three consecutive strong starts by limiting the Reds, Diamondbacks and Astros to four runs in 20 innings. But he regressed by making three poor starts earlier this month, including losses of 16-7 to the Rockies and 10-4 to the Dodgers.

"We're looking forward to getting him back, but we're not going to rush him," Tracy said.