Ricky Stone, a 6-foot-1, 195-pound right-handed reliever, was claimed from the Houston Astros just prior to the deadline and made it into San Diego in time for last night's game.
Stone became available when the Astros acquired two relievers from the Mets in exchange for Richard Hildago.
To make room for Stone on the 25-man roster, the Padres optioned outfielder Jon Knott to Triple-A Portland.
Knott, 25, batted .214 (3-for-14) with two doubles and one RBI in nine games with the Padres.
He had his contract purchased by the Padres on May 28 and made his Major League debut on May 30 as a pinch hitter against the Milwaukee Brewers. Knott, who led the Pacific Coast League in RBIs and ranked third in homers at the time of his promotion, joined the Padres after left fielder Ryan Klesko was placed on the 15-day disabled list with a strained oblique.
Stone, 29, made 16 relief appearances with the Astros this season, going 1-1 with a 5.68 ERA. Over parts of four seasons with Houston (2001-2004), Stone had a career record of 19-8 with two saves and a 3.80 ERA in 165 games, all in relief.
"I'm very excited coming here," said Stone. "Hopefully I can contribute any way I can.
"The Astros had to make some moves and I was one of the ones who was chosen. Like I said, I'm happy to be over here to get a fresh start and hopefully help this team out."
And with the Padres tailspin hitting its height against the American League, fresh blood was needed to inject some enthusiasm and fight back into the bullpen.
"Ricky Stone has experience and has been pitching middle relief," Bochy said. "He's got four pitches and is a Major League pitcher."