Recapping the injury updates (plus Klein)

Orioles manager Buck Showalter confirmed earlier today that Jeremy Guthrie will start tomorrow night against the Pirates. Jason Berken would have taken the ball in Guthrie's absence. Guthrie left his last start in Toronto because of a strained muscle in his upper back. An MRI didn't reveal anything more serious and he threw a bullpen session yesterday in Washington.

Also, Showalter told reporters that Brian Matusz could be pushed back to Saturday night, with Chris Jakubauskas going on normal rest Friday night. The open date on Thursday allows Showalter to tweak the rotation. The good news here is Matusz's hamstring is fine and he'll start against the Reds at Camden Yards. Night to be determined. Luke Scott's back has improved enough that he's available tonight. Also, second baseman Brian Roberts will fly into Pittsburgh tonight and be reevaluated tomorrow by Dr. Michael Collins. And the Orioles are expected to name a new bullpen coach on Thursday. As Showalter stated a few days ago, the club could rotate a few individuals from within the organization, rather than go with one replacement for Rick Adair. Klein update: Dr. Lewis Yocum examined Double-A Bowie pitcher Dan Klein today in California, but the Orioles aren't expecting to receive the results until tomorrow afternoon. Yocum compared MRIs taken on Klein's shoulder last week and after the club drafted him in the third round in 2010 out of UCLA. Klein didn't undergo an MRI today. Last week's MRI in Baltimore raised some concerns within the organization, though the results weren't conclusive. The Orioles sent him to Dr. Yocum, who cleaned out Klein's shoulder back in 2009. Klein was hoping that the discomfort in his shoulder was caused by biceps tendinitis that eventually would subside with rest and medication. The Orioles wanted to promote Klein to Triple-A Norfolk, but those plans have been shelved. He's a combined 3-1 with a 1.11 ERA between Single-A Frederick and Bowie, with six walks and 37 strikeouts in 32 1/3 innings. Pitcher Oliver Drake has been promoted from Single-A Frederick to Norfolk because the bullpen has been taxed after abbreviated starts by Chris Tillman (rain delay) and Steve Johnson over the weekend.