BALTIMORE -- Orioles shortstop J.J. Hardy will undergo an MRI on his left oblique on Monday, although early indications regarding his injury are that he could miss up to six weeks.

Hardy had a conversation Saturday night with his friend Corey Hart, the Brewers outfielder. Hart also suffered a left rib-cage strain and is finally turning the corner in his recovery. The Orioles are worried that Hardy -- who will report to extended spring camp on Monday -- could miss an extended amount of time.

"It's not good," Hart said of Hardy's diagnosis. "They thought mine was going to be minor, and here we are six weeks later. Maybe I'm not a quick healer. It's a tough thing -- you try to push it and all of a sudden you're pushed back three days. It's crazy how everybody is getting them."

The team will know more regarding Hardy following Monday's test. In the meantime, O's manager Buck Showalter will go with middle-infield backups Robert Andino and Cesar Izturis. Hardy's loss is a big blow for the Orioles, who traded for the shortstop this offseason to provide some extra offense at the bottom of their order. Hardy had a solid spring but had been hampered since Thursday with tightness in his left side.

In six games, he had three hits -- all doubles -- and two RBIs, scoring four runs and walking twice.

-- Adam McCalvy contributed to this report.

Assignments congealing for Yanks series

BALTIMORE -- With Jeremy Guthrie making Sunday's start in the Rangers-Orioles series finale, the pitching assignments for the Orioles' upcoming series against the AL East rivals New York Yankees have become much clearer.

Chris Tillman will start Tuesday's opener in New York, and Jake Arrieta -- who pitched the second game of Saturday's doubleheader -- will pitch Thursday's finale, leaving rookie Zach Britton to pitch the first game in the Cleveland series on Friday. The thought is that Arrieta has pitched at Yankee Stadium before and Britton -- who faced the Yanks several times this spring -- would be a better option for next weekend's opener. Arrieta has fared well against New York, going 2-0 with a 3.65 ERA in two career starts.

Wednesday's starter will be either Chris Jakubauskas on three days' rest or Brad Bergesen, who was optioned to Triple-A Norfolk on Saturday. The team would prefer to let Bergsen get back on track in Norfolk, and using Jakubauskas (who threw three innings on Saturday) would be the easier route roster-wise. But that decision depends on the state of the bullpen, among other factors.

If the O's recall Bergesen, they will have to use the roster spot freed up by shortstop J.J. Hardy, since clubs can only recall an optioned player in less than 10 days if there is an injury. While Hardy going to the disabled list is all but official -- he is expected to travel to extended spring camp with Brian Matusz on Monday -- the O's could use that extra roster spot for another reliever or a position player if they give Jakubauskas the start.

Jakubauskas went three innings in relief on Saturday night, throwing 51 pitches and facing 16 batters. The right-hander allowed five earned runs. Bergesen pitched just one game before he was optioned, starting against the Detroit Tigers on Wednesday. He allowed four runs (two earned) in 3 2/3 innings.

Worth noting

• Orioles starter Brian Matusz will fly to Sarasota, Fla., on Monday to start his progression back from a left intercostal muscle strain. Matusz, who has been with the team since going on the disabled list on April 1, said there is no set timetable but he's "optimistic" given that the pain has subsided since Thursday. The challenge will be not getting carried away. "That's going to be the hardest part because I've wanted to play catch so badly the past few days," Matusz said. "It's been fun [being with the team] but I'm looking forward to getting back out there."
• Vladimir Guerrero received his 2010 Players Choice Award as AL Comeback Player of the Year and Silver Slugger award in a pregame ceremony Sunday. Guerrero played for Texas during the 2010 season.
• Chris Jakubauskas made his Orioles debut with three innings of relief on Saturday night. It also marked the first time Jakubauskas had appeared in a Major League game since April 24, 2010, a game in which he was struck in the head with a line drive after recording just two outs. "If you don't take in a moment like that, you're not watching as a coach or a manager or a teammate," Showalter said. "I'm sure some of the guys may not be completely aware of what's going on and the long haul it took for him to get there."