A reliever the past four years before an offseason trade that sent staff ace Dan Haren to Arizona and opened a spot in the A's rotation, Duchscherer struck out six and walked two. He left in the sixth after giving up back-to-back singles to Kelly Shoppach and Grady Sizemore.
Duchscherer, who had season-ending surgery on his right hip last July, retired the first 11 batters he faced. He threw only 72 pitches before being taken out of the game following a meeting on the mound with Oakland head trainer Steve Sayles.
While there was initial concern that Duchscherer (1-0) might have aggravated his hip, the A's later announced that he was suffering from "slight biceps tendinitis."
Cleveland starter Paul Byrd also had his problems, but they weren't physical.
The Indians' right-hander struggled with his control in the first two innings, walking the second batter he faced and hitting two more in the second. Kurt Suzuki, one of the two A's batters hit by Byrd, later scored on a passed ball.
The A's, scoreless in their previous 16 innings prior to Friday, chased Byrd in the fifth when they batted around to make it 5-0. Suzuki and Ryan Sweeney, who went 4-for-4, both had RBI singles for Oakland.
Byrd (0-1) gave up five runs and eight hits while taking the loss.
Garko and Travis Hafner both homered for the Indians.