Is Oakland's Sheets tipping his pitches?

Buster Blog: Ben Sheets (2:52)

Buster Olney talks about Ben Sheets tipping his pitches (2:52)

Is Oakland pitcher Ben Sheets tipping his pitches, most notably his curveball? In his last two starts, spanning 7 1/3 innings, Sheets has been shelled for 17 runs on 19 hits. ESPN The Magazine's Buster Olney discusses.

Side note: The Rangers will miss Sheets on this trip to Oakland, and quite possibly during the A's trip to Arlington on May 11-13. He's next scheduled to start Saturday against Tampa Bay.