CLEVELAND -- The Indians have their ace back for the postseason push. All-Star starter Justin Masterson is returning in relief.

Masterson, sidelined since Sept. 2 with a strained oblique muscle, has been cleared to pitch and could be on the mound as early as Wednesday night against the Chicago White Sox as the Indians try to hold onto one of the AL's two wild-card spots.

It's unlikely Masterson will start again this year unless the Indians play deep into October, but manager Terry Francona said it will be nice to have the right-hander as an option out of the bullpen as Cleveland tries to clinch its first playoff appearance since 2007.

"What ended up possibly being a big negative for us -- having Masty not around -- all of a sudden has a chance to be a big weapon for us moving forward," Francona said.

Masterson, who went 14-10 with a 3.52 ERA in 29 starts before he had to be pulled in the second inning of a start against the Baltimore Orioles, hasn't pitched in relief since 2008, when both he and Francona were with the Boston Red Sox.

"It's been quite some time, especially with any significance," Masterson said before joking about becoming the 16th reliever in Cleveland's bullpen. "We have like 100 guys down there, too. I might have to sit in the bathroom."

Kidding aside, the Indians are thrilled to have Masterson available down the stretch.

Masterson pitched in a simulated game Sunday after the Indians completed a four-game sweep of the Houston Astros. With Progressive Field's stands empty, Masterson worked in front of Francona, Cleveland's coaches and general manager Chris Antonetti. It was Masterson's final hurdle before he could be cleared to return.

"He did terrific," Francona said. "His stuff was really good. He wasn't down that long and it shows."

Masterson said he pitched as if it was a "real" game.

"I gave it all I got, to really try and test myself to see what we got," he said. "I threw just one inning, but it felt pretty good after that."

While Masterson said he'd love to start again this season, he wants to be smart and the Indians will be cautious with the 28-year-old, who was having his best season before the injury.

However, if Cleveland can advance beyond the division series, it's possible Masterson could start again.

"That would be part of the goal," he said. "What we want to do is make sure we're not getting too greedy and get where we want to, so I'm not counting anything out. However we can help the team. Because I want to make sure that, although I feel good, will we still be great over four or five innings?

"Ultimately that's how I like to do things -- go as deep as I can. That's why we want to make sure we're in the right position for that so we're not hurting our team when it comes time for something like that."

Masterson acknowledged that it's been frustrating not being able to help his teammates, but he's been pitching in as best he can.

"It's great because we're winning ballgames," he said. "That's been fun. The guys are going out there and playing hard. Look at Ubaldo [Jimenez]. He's been tremendous for us and that's what you would like to see, and everyone else is picking it up.

"They don't need me. I'm just here to encourage and smile and give them hugs. It seems like that's working right now."