KANSAS CITY -- Orioles second baseman Brian Roberts underwent a root canal on Tuesday, keeping him out of the lineup for the series opener in Kansas City.

"Hopefully, I'll be playing [Wednesday]," Roberts said.

Roberts was in some discomfort on Sunday, but played through it. During the Orioles' plane ride from Chicago to Kansas City on Monday night, Roberts began to experience severe pain.

"By the time we landed, we knew he had a problem," Orioles manager Buck Showalter said.

The Orioles were able to get Roberts a morning dental appointment after he had a sleepless night. Following the procedure, Roberts went to the hotel for a nap and then reported to Kauffman Stadium around 5 p.m. CT

"I think anybody who has had a root canal knows what we're talking about," Showalter said. "Hopefully, it's something that doesn't keep him down very long."

Hardy could begin rehab stint on Friday

KANSAS CITY -- Orioles shortstop J.J. Hardy, recovering from a strained left oblique, may begin a rehab assignment on Friday according to manager Buck Showalter.

Showalter said Hardy would play either for Class A Frederick or Triple-A Norfolk if he experiences no setbacks. Showalter noted that both affiliates have home dates scheduled.

In other injury updates, Showalter said left-hander Brian Matusz (strained left intercostal muscle) had a good day and will throw a bullpen session and batting practice on Wednesday. Right-hander Justin Duchscherer threw 30 pitches in live batting practice Tuesday and reported no pain.

"We'll take it day-to-day with [Duchscherer]," Showalter said.

Markakis plays despite bumps and bruises

KANSAS CITY -- Bumps and bruises aside, Orioles right fielder Nick Markakis arrived at the ballpark ready to go on Tuesday.

Markakis, who was hit on the right hand Monday and also hit his knee in the outfield, shrugged off any soreness as simply part of the game.

"It's no big deal," Markakis said. "I'm good to go. It's a little sore, but it's not something I haven't been through before. There are bumps and bruises all along the way."

Tuesday was Markakis' 28th game for the Orioles this season.

Pitchers share credit for Wieters' throwing

KANSAS CITY -- One of Buck Showalter's missions in Spring Training was emphasizing to the Orioles' pitching staff how important it was to keep baserunners close to the bag.

So far, so good. Catcher Matt Wieters went into Tuesday's game having thrown out six of 12 runners trying to steal. Wieters gets a lot of credit, but so do the pitchers.

"You teach guys how to throw a changeup and talk about deliveries, but you also have to teach them how to hold runners," Showalter said. "You can't come up here at 1.5 or 1.6 [seconds to the plate] and expect to compete. Matt has been real impressive defensively, but he'll be the first to tell you that the pitchers have given him a chance. We told [the pitchers] in the spring that if you'll just give this guy a chance, he'll take care of you."

Guerrero earns first walk with Orioles

KANSAS CITY -- It took 28 games, but Vladimir Guerrero finally took a stroll in an Orioles uniform. Guerrero had gone 115 plate appearances without a walk when he took ball four from Royals' left-hander Jeff Francis in the sixth inning of Tuesday's game at Kauffman Stadium.

The free-swinging Guerrero was the first non-pitcher in franchise history to not have at least one walk by that mark.