The Astros, who are joining the American League West in 2013, have come to Pittsburgh yearly since 1962 and quite frequently since 1994, when the Astros and Pirates both joined the newly-created National League Central.
"It is kind of weird," reliever Wesley Wright said. "You're used to seeing that on the schedule in the Central, and now we are switching leagues. It's kind of bittersweet, but it's also exciting to get a chance to see some different places."
The Astros are 136-214 all-time in Pittsburgh (Three Rivers Stadium and PNC Park) heading into Wednesday's rubber game.
Left-hander Fernando Abad, who started the year in the bullpen, will make his third career start for the Astros. He's 0-2 with a 7.56 ERA in two starts.
The Pirates, who ended a four-game losing streak on Tuesday and are looking to make up ground in the NL Wild Card race, give the ball to right-hander Kevin Correia.
Correia was pulled from the rotation on July 25 and will be starting in place of Jeff Karstens, who is dealing with a strained hip flexor. Correia last started on Aug. 20 and went 4 1/3 innings against the Padres, allowing three runs (two earned) on seven hits.
Correia has made two long relief appearances out of the bullpen since his last start, allowing one run over 6 1/3 innings.
Against the Astros on July 4, Correia gave up three runs over six innings and earned the victory.
Astros: Martinez simplified swing at Triple-A
Outfielder J.D. Martinez, the Astros' leader in RBIs, worked on simplifying his swing while spending nearly a month with Triple-A Oklahoma City. Martinez was one of four players called up on Tuesday.
Martinez batted .235 with 11 homers and 54 RBIs before being sent down on Aug. 9. He played 23 games for Oklahoma City and hit .233 with six doubles and four RBIs. Triple-A hitting coach Leon Roberts helped Martinez with his swing.
"We just worked on simplifying everything, trying to get back to what made me good and what made me effective -- what parts of my swing used to stand out," Martinez said. "We watched a lot of film. He gave me his advice. I listened to it. We tried some things. Some things worked. Some didn't. Here I am now."
Astros interim manager Tony DeFrancesco, who coached Martinez for a couple of weeks before being promoted from Oklahoma City, wants Martinez to eliminate some of the extra movement in his stride and his hands.
"Sometimes the fastball's on top of him and he just can't react as quick," DeFrancesco said.
Pirates: Jones on hot streak at the plate
Garrett Jones, who spent the first couple of months of the season as a platoon first baseman, is batting .440 (11-for-25) since last Tuesday. His season average is up to .292, nearly 40 points higher than his career average entering this season.
He went 1-for-3 with an RBI and a walk on Tuesday.
"I'm just feeling comfortable. I'm seeing the ball well," Jones said.
"When you're swinging the bat well, the ball's bigger and everything seems to slow down," manager Clint Hurdle said. "He's in a very good place at the plate now. He's aggressive within the strike zone and has a lot of confidence."