Mark HendricksonAmong the story lines for the Orioles in Spring Training is Mark Hendrickson‘s return to professional baseball as a sidearm relief pitcher. The tall lefty last pitched in the big leagues with the O’s in 2011 and signed a minor league deal with an invite to spring training with Baltimore after participating in their three day mini camp in January.

Last season he played down the road in York with the Revolution of the independent Atlantic League.

Hendrickson’s opted to reinvent himself as a sidearm pitcher after Orioles skipper Buck Showalter recommended the change in 2011. “It’s a work in progress,” Showalter told Eduardo Encina of the Baltimore Sun last month. “He knows it. It’s something he’s been doing for just a couple months. It’s something that’s been very intriguing for everybody about presentation. We think it’s something nobody’s ever seen. I think everybody’s a little intrigued to see how it plays. There’s no one who is 6-9 who throws from that arm angle.”

A deep, strong bullpen may make Hendrickson’s chances of a comeback even more difficult, but if he can master the arm slot he’d offer the O’s something no one else does on the staff. Troy Patton is the only lefty in the bullpen (assuming Brian Matusz makes the starting rotation).

This isn’t the first time Buck Showalter was worked with a pitcher on a dramatic change in his style. R.A. Dickey earned his spot in Texas’ rotation through the help and support of Showalter back in 2006.

No one expects Hendrickson to become the next Dickey, but would anyone be surprised if he turned out to be an effective reliever for the O’s this season?