"I think it's in his best interests and the best way to get him through the entire season," Trembley said. "There will be more opportunities for him to be successful and for us to win."
Hampered last season by a left hamstring injury and a partial tear in his right flexor tendon, Uehara was shut down for good in mid-September and reported to Sarasota early to start throwing. The 34-year-old had his first mound session on Tuesday at the team's Minor League facility at Twin Lakes Park and wasn't informed of Trembley's decision until Thursday morning, before the players took the field for the first pitchers and catchers workout.
"He agrees with [the reasoning]," Trembley said. "Koji has been nothing but tremendous with me. He has been very cooperative. He's a team guy."
Given the Orioles' crowded projected rotation of Kevin Millwood, Jeremy Guthrie, Brad Bergesen, Brian Matusz and Chris Tillman, plus last year's starters David Hernandez and Jason Berken, adding Uehara to the 'pen will certainly make the relief corps stronger.
"I think he can fit a number of roles for us," said pitching coach Rick Kranitz, who believes Uehara is better suited for the bullpen given his two-pitch arsenal.
"He puts guys away with his command and he puts guys away with his splitter," Kranitz said. "If he's throwing anything like he threw [at times] last year, he's going to be a huge help to us."
Uehara went 2-4 with a 4.05 ERA in 12 Major League starts last season, but he held opponents to a .202 average in their first plate appearance. That average raises nearly 100 points, to .292, the second time around the batting order.
Given his starting experience, if Uehara can stay healthy, he could serve as a multi-inning bridge reliever or late-inning setup man. Kranitz also entertained the possibility that Uehara could give eighth-inning guy Jim Johnson or closer Michael Gonzalez a night off if necessary. Uehara has had bullpen experience in Japan, spending one season as a closer.
"It's all about the team, team first," Uehara said through interpreter Jiwon Bang on Wednesday. "So as long as the team wants me to [pitch out of the bullpen], I'll follow."
Brittany Ghiroli is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.