PITTSBURGH (AP) -- Oliver Perez, the power-throwing but puzzling left-hander who was Pittsburgh's opening-day starter, was demoted to the Pirates' bullpen Tuesday during the team's longest losing streak in more than 50 years.
The Pirates also designated long reliever Ryan Vogelsong for assignment and recalled right-hander Jonah Bayliss from Triple-A Indianapolis.
Manager Jim Tracy did not immediately name a replacement for Perez in a rotation that had remained intact all season until right-hander Victor Santos (rotator cuff) went on the disabled list June 18. Left-hander Tom Gorzelanny (6-5, 2.35 ERA) is expected to be called up from Indianapolis to start Saturday against Detroit.
Despite managing general partner Kevin McClatchy's weekend comments that the Pirates need changes, general manager Dave Littlefield said he won't shake up their roster despite an 11-game losing streak going into Tuesday night's game against the White Sox. The slump is the team's longest since 1955.
"Overall, there isn't going to be one more or a series of moves that changes drastically the makeup of the team," Littlefield said. "What we need is to get back on track and play better baseball."
The 24-year-old Perez appeared to have a breakthrough season while going 12-10 with a 2.98 ERA and 239 strikeouts in 2004, the year after being acquired with Jason Bay from San Diego. But he slumped to a 7-5 record and 5.85 ERA last season and has been even worse this season, going 2-10 with a 6.63 ERA.
Perez has allowed 24 earned runs in 23 1-3 innings over five starts this month, all losses. Pittsburgh lost all but one of the five starts by at least six runs.
"The thing we've been dealing with is that Oliver is at either end of the spectrum," Tracy said. "Either he's really, really good or way off. In trying get him back to the point where he reaches consistency, we'll be using him out of the bullpen for a period of time."
The Pirates, mainly pitching coach Jim Colborn, have worked since spring training to get Perez to smooth out his delivery, maintain a consistent delivery and release point and to calm his emotions on the mound.
Tracy thinks Perez might pitch better by not knowing which days he will pitch.
"Maybe (it will help) not having to sit around and dwell too much on some of the information that's been passed along to him -- sometimes we see him grab hold of it, and then like that he just loses it," Tracy said. "Right now, we don't know which guy is coming every fifth day and that's tough to deal with."
The Pirates finally appear to have given up on Vogelsong, the key player in the deal that sent right-hander Jason Schmidt to the Giants in 2001. Vogelsong went 6-13 with a 6.50 ERA in 31 games in 2004, but has since pitched out of the bullpen. He had no record and a 6.39 ERA in 38 innings this season, most in mop-up roles.
"You don't ever want to get released or designated, but maybe this will be the best thing for me," said Vogelsong, who is 28. "Maybe I was the reason we were losing games, I don't know."
The 25-year-old Bayliss was 0-0 with a 4.63 ERA in 11 games with Kansas City last season before being acquired by Pittsburgh in an offseason trade that sent left-hander Mark Redman to the Royals. Bayliss was 3-1 with a 1.77 ERA in 27 games at Triple-A.