A few pregame hits from Citi Field

FLUSHING, N.Y. - Orioles reliever Darren O'Day and outfielder Colby Rasmus have joined Single-A Frederick tonight for a rehab game in Potomac.

O'Day will work one inning in his first game since hyperextending his right elbow. He's been on the disabled list retroactive to May 6.

The Orioles are hoping that O'Day is ready to come off the disabled list Thursday in Toronto.

Meanwhile, O'Day has officially reached 10 years of service time in the majors. He's a 10-5 guy who can veto any trade.

Rasmus was 0-for-6 with a walk in two games at Double-A Bowie. He's been on the DL since April 7 with a strained left hip flexor.

Zach Britton will pitch tonight for Triple-A Norfolk in Columbus.

The rotation is staying in order despite Sunday's rainout and Monday's off-day. Everyone is pushed back, which puts David Hess in Toronto for Thursday night's series opener.

The Orioles are carrying two rookie catchers on their 25-man roster with Chance Sisco and Austin Wynns, the first time it's happened since 2008 with Guillermo Quiroz and Omir Santos, according to STATS.

Wynns is catching Alex Cobb for the first time besides Sunday's bullpen session. They also played catch and chatted, with more detailed game planning coming before first pitch.

"Learning from that and just seeing what he does," Wynns said. "I want to be on the same page. I've got to be eye to eye with him, and we'll talk more soon."

The Mets are starting left-hander Jason Vargas, which made Wynns the most logical candidate to work behind the plate. Sisco is expected to catch Dylan Bundy in Wednesday afternoon's series finale.

Wynns wasn't told that he'd be starting tonight. He checked the lineup card and found his name.

"I'm just assuming that every day," he said. "Every day be ready, no matter what. That's my mentality. Every day, you're playing until they say 'no.' And you never know.

"End of the game, something happens, a situation comes up and I could come up. No matter what, just be ready. Always be ready."

The Orioles announced that Kyle Moore will manage the short-season Single-A Aberdeen IronBirds for the 2018 season. Kevin Bradshaw suffered a season-ending injury and will remain in Florida while he recovers.

Moore was the hitting coach at Frederick.