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06/27/12 3:50 PM ET

Colon progressing, set for bullpen session

SEATTLE -- Though oblique injuries normally lead to an extended absence for athletes, A's hurler Bartolo Colon is working against those odds and progressing at an encouraging rate.

The right-hander incurred the injury to his right oblique less than two weeks ago, yet manager Bob Melvin reported Wednesday that Colon is already scheduled to throw a bullpen on Thursday in Texas. He's eligible to come off the DL on Tuesday.

"After he had the injury, I was surprised to see him coming along as quickly as he has," Melvin said. "I really didn't think at the time he'd have a chance to pitch in a game before the All-Star break, but there's a possibility of that."

The 39-year-old Colon, who has already given the A's 89 2/3 innings of work this season, was 6-7 with a 4.22 ERA in 15 starts before being sidelined. His injury coincided with righty Brandon McCarthy's recurring shoulder issues, leaving the A's two veteran rotation spots to fill. Yet they've managed just fine with fill-ins Tyson Ross and rookie A.J. Griffin, and Oakland starters entered Wednesday having posted a 1.77 ERA and .160 opponents average over the last 12 games.

"It's good to see," Melvin said. "Some of the younger guys that we haven't seen as much, like a Griffin, are doing well. I think it becomes something where they're pushing each other. One guy sets the bar and has a good game, and the next guy goes out there and tries to better. It kind of becomes a competition amongst pitchers to keep it on a roll."

Worth noting

• Left-hander Brett Anderson, on the mend from Tommy John surgery, threw a 30-pitch bullpen in Seattle on Wednesday, using fastballs and changeups.

"Free and easy," manager Bob Melvin said. "Before he had a little bit of a setback, he was getting close to potentially pitching in a game, so we'll go through this route again. Everything feels good, and obviously we're going to be careful with him. He's a guy we're looking forward to getting back but certainly not one we're going to rush."

Anderson's next bullpen session will come Sunday in Texas.

• Jemile Weeks received the day off Wednesday, with Brandon Hicks getting the start in his stead at second base. Weeks, who was battling some leg soreness in recent weeks, is hitting just .205 over his previous 12 games, but he stole his first base -- 11th of the season -- in Tuesday's game, snapping a streak of 35 contests without a steal.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.