"We want to see how this unfolds with Tatum," manager Dave Trembley said after Tuesday's 10-9 loss to the Detroit Tigers.
"This doesn't mean that it's etched in stone, but we want to give Tatum a shot. We like the way he throws, and we're confident that he can work with the pitchers, and [pitching coach Rick] Krantiz and [bench coach Jeff] Datz on the game reports and scouting reports. We want to give him an opportunity to do that."
The move comes as a surprise given that Moeller stayed with Baltimore with the expectation being that he would help mentor starting backstop Matt Wieters. The 35-year-old Moeller was lockermates with the 23-year-old Wieters and had built up an impressive reputation around the clubhouse given his general likeability and knowledge of the game.
"Moeller's been around," Trembley said. "He's the epitome of a professional."
A California native, Moeller has spent parts of nine seasons in the Majors, including 30 games with Baltimore last year. Trembley said president of baseball operations Andy MacPhail told Moeller that the Orioles would actively check with all 29 other teams to see whether there's any chance he can catch on in the Majors elsewhere.
If not, the Orioles would love to have a seasoned veteran like Moeller help mold a Triple-A Norfolk rotation that is expected to include prospects Jake Arrieta, Troy Patton, Brandon Erbe, Chris Tillman and Alfredo Simon.
"[Moeller] understands very well, and it's difficult for him right now," Trembley said. "He's 35; the days of his career are dwindling. I told him we'd love to have him go to Triple-A."
"He's going to have to come to us and tell us what he wants to do."
Moeller wasn't sure what the next step was for him and said he planned to talk to his family first. Obviously any Major League interest from another club could alter his plans significantly.
As expected, Moeller's move wasn't well-received news in the Orioles clubhouse. But Trembley saw the decision in a different light.
"This is Wieters' team; this is Wieters' pitching staff," Trembley said. "We're expecting an awful lot of Wieters. Chad Moeller is not there for Wieters anymore."
"I think it's a compliment instead of a negative that should be taken by the clubhouse."
The move was defense-oriented, as the Orioles are high on Tatum's arm and thought Moeller wasn't as good at throwing out baserunners. Any offense provided from Tatum -- who went 2-for-5 with an RBI on Tuesday -- would be a bonus.
Claimed off waivers from Cincinnati in the offseason, Tatum has appeared in a career 26 Major League games. This will be his first Opening Day roster.