Wang got off to an awful start this season before going on the disabled list with weakness in the adductor muscles in his hips. He has pitched well since he was activated May 22, allowing two runs and nine hits in eight innings over three relief appearances to lower his ERA from 34.50 to 16.07, and he is to start Thursday against Texas.
Wang threw two scoreless innings at the Rangers on May 27 and followed that up with three shutout innings against Cleveland on Sunday, convincing the Yankees he was back to the form that helped him win 19 games each in 2006 and 2007.
"We weren't just going to move him to move him," manager Joe Girardi said. "We had to feel that his stuff was back and watching him these last two times has made us feel that his stuff is back."
The move splits up Andy Pettitte and Sabathia, the left-handers in New York's rotation, and gives Sabathia an extra day of rest.
Wang, who missed the final 3½ months of last season after severely injuring his right foot while running the bases in Houston, was happy about the switch. He acknowledged he didn't like the bullpen very much.
"[It's] very hard because you don't know when you're going to pitch," he said.
Both Girardi and general manager Brian Cashman said moving Joba Chamberlain back to the bullpen wasn't considered.
Hughes, who joined the rotation when Wang went on the DL, is 3-2 with a 5.45 ERA in seven starts this year. He said his two games in the 2007 AL division series against Cleveland are the only times he has worked out of the bullpen in his life.
"I'll do whatever the team needs," Hughes said. "Right now that's being in the bullpen."
Hughes' time as a reliever could depend on the health of Brian Bruney, sidelined with a right elbow strain. The Yankees want to keep Hughes stretched out in case they need a starter down the road and could send him to the minors once Bruney returns in order to keep his pitch count up.
Bruney threw from about 90 feet before New York's game against Texas on Wednesday night and Girardi said he felt good.
"We'll see how this plays out over the next few weeks," Cashman said. "It's certainly tied to Brian Bruney."
Cashman also acknowledged that his phone has been ringing with more frequency since Wang returned.
"People have reached out and called about our starters, seeing if there is an opportunity here to pry things away," he said, "if we were somehow of the mindset that this is too much for us to handle. I've just responded we're going to choose to embrace this."
Hughes won't be available until Friday, and New York also was down a position player for Wednesday night's game against the Rangers, losing first baseman Mark Teixeira to a bruised right ankle. Teixeira was injured when he made a hard slide into Texas shortstop Elvis Andrus to break up a double play in Tuesday night's 12-3 victory -- New York's 16th win in 20 games.
Nick Swisher moved from right field to first, Melky Cabrera switched from center to right and Brett Gardner came in to play center when Teixeira was scratched. Swisher batted second, and Johnny Damon was third in the lineup.
X-rays on Teixeira's ankle were negative, and he was day to day.