McGehee, 29, will be asked to help the Yankees at the corner-infield positions while Alex Rodriguez and Mark Teixeira are sidelined with injuries. McGehee has played mostly third base during his five-year big league career, but Pittsburgh had primarily used him at first base this year.
"He gives us another right-handed bat," Yankees general manager Brian Cashman said. "McGehee can obviously be a right-handed bat off the bench, he can play first base, he can play third base, he can DH."
The Yankees also received cash considerations in the deal for McGehee, who is earning $2.5 million this season and was batting .230 with eight home runs and 35 RBIs in 92 games. McGehee is expected to join the Yankees for Wednesday's series finale against the Orioles and is excited to head to New York.
"I haven't spent too much time in a real big city," McGehee said. "I played there once as a visitor [in 2011]; it's definitely an experience. I've got the easiest part -- I get to go play baseball; that's always a calming influence on me. ... I get a chance to go play for arguably the greatest franchise in the history of sports, so there's something to be said for that."
To immediately replace Qualls on the active roster, the Yankees summoned right-hander Joba Chamberlain to rejoin the club at Yankee Stadium; Chamberlain had been on his way to make a Minor League rehab appearance at Double-A Trenton and arrived in the Bronx shortly before 6 p.m.
Cashman said he was anticipating a quiet Trade Deadline for the Yankees, noting that asking prices in the marketplace seemed to be high, but the Yankees reportedly engaged in talks with the Cubs to acquire right-hander Ryan Dempster late in the afternoon when Chicago's potential deal with the Dodgers fizzled.
Dempster had some ties to the Yankees; he played under pitching coach Larry Rothschild and was signed by then-Cubs GM Jim Hendry, now an assistant to Cashman. Dempster went as far as informing the Cubs that he would approve a trade to the Yankees, but he was dealt instead to the Rangers.
"There's a lot of things that get presented, ideas thrown around, a lot of different concepts," Cashman said, refusing to address the Dempster talks directly. "It's our job to vet them all, and obviously what we did today is the Qualls deal for McGehee."
Manager Joe Girardi said that missing out on a new addition to the starting rotation wouldn't be a huge blow to his American League East-leading Yankees.
"Our rotation has thrown really pretty well," Girardi said. "You look at what all the guys have done; we expect Andy [Pettitte] to come back here. I know it won't be for a little bit, but we expect him to come back. And in the midst of the struggles we've had recently, it hasn't been our rotation. I've been pretty pleased with it."
Now that the non-waiver Trade Deadline has passed, deals involving players on the 40-man roster cannot be made unless the players already have cleared waivers. In other words, the player must be offered to the other teams in reverse order of the standings, and if he is claimed by one of the teams, he cannot be traded. The club that placed the player on waivers can either withdraw the request and keep the player or let the player go to the claiming team, which would then have the rights to the player.
McGehee has appeared in 77 games at first base and nine at third base for the Pirates this year. A lifetime .260 hitter, he has also played for the Cubs (2008) and Brewers (2009-11). He finished fifth in voting for the National League Rookie of the Year Award in 2009, when he hit .301 with 16 homers and 66 RBIs for Milwaukee.
"We feel that he can play third and first for us," Girardi said. "With Tex not being available for a few days, with Alex not being available for weeks, this is a guy that has put up big numbers in his career, and we're hoping he can help us."
Cashman said that the McGehee trade materialized in the past week as Pirates GM Neal Huntington was exploring some other moves.
"He just wanted to give me a heads-up earlier in the week," Cashman said. "[Huntington said], 'Hey, I might be calling you if a couple of things work out a certain way, so it's possible on the 31st I might have a conversation if you're still interested in that certain situation.' I said fine, so we were prepared for it, and a call did come."
Qualls, 33, combined to go 2-1 with a 4.89 ERA in 43 relief appearances with the Phillies and Yankees in 2012. Acquired by the Yankees from the Phillies on July 1 for cash considerations, Qualls made eight appearances with New York, going 1-0 with a 6.14 ERA.
Cashman rejected the suggestion that he seems to be comfortable with his current roster, which entered play on Tuesday 18 games above .500 at 60-42 despite a three-game losing streak.
"Until you get what you want, which is a World Series trophy, you're never comfortable," Cashman said. "You're always looking at ways to try to improve your club. Obviously you're not allowed to do so after Aug. 31, other than what you have. The only time that mentality stops is if you're the last team standing. Otherwise, you were never close enough."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.