One of the major reasons for the Orioles' surprising beginning to the 2012 season has been the acquisition of Jason Hammel. And while he's seemingly on track to avoid a stint on the 15-day disabled list, his balky knee is becoming a cause for concern. Hammel was scheduled to start Thursday, but he's been scratched from that due to the knee issue.

"There's fluid and inflammation, other than that maybe an old injury that had been re-aggravated," said Hammel (MLB.com), referencing knee surgery back in 2008. "Nothing fancy. Other than that, just enough to [aggravate] my knee."

The MLB.com report indicates Hammel's knee has "progressively worsened over his past two or three starts," but that he doesn't believe he'll hit the disabled list.

"I'm very confident about that," said Hammel (MLB.com).

With Wednesday night's Orioles-Rangers game postponed due to rain, there will be a doubleheader. Wei-Yin Chen will start Game 1 while Tommy Hunter is pitching Game 2.

Hammel, 29, has been a revelation for the Orioles this season. He's 4-1 with a 2.09 ERA, 0.98 WHIP and 38 strikeouts in 38 2/3 innings.

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