BALTIMORE -- The Orioles opened up a gaping hole in their infield and their lineup Sunday, when Brian Roberts was forced to the disabled list with a strained left groin. The second baseman will be gone for two weeks, and Brandon Fahey will fill in for him on defense. For now, center fielder Corey Patterson will be Baltimore's leadoff hitter.

"We feel like he's probably 10 days away, at least," Baltimore manager Sam Perlozzo said of Roberts' return. "Usually when a guy's ready in 10, you give him a couple extra. This is a situation where we need Brian for the long haul."

Roberts was originally bothered by a left hip flexor, and the ailment got progressively worse over the last week or two. The switch-hitter still has nine stolen bases in his last 10 games, but Perlozzo said he was incapable of playing for the next few days. That made the decision an easy one for the Orioles, who have other injury concerns to worry about.

Miguel Tejada, for instance, is dealing with a balky left hamstring injury that limited him to designated hitter duty on Sunday. Baltimore is also missing Javy Lopez and Kevin Millar, who are both day-to-day with minor ailments of their own. That leaves the O's with two healthy bench players -- backup catcher Raul Chavez and backup outfielder Luis Terrero.

"We're going to have to battle through it. Some other people are going to have to pick up the slack," Perlozzo said. "The only real problem right now that I would possibly have is Ramon [Hernandez] is going to have to be in there. But he's had some days off. He should be able to handle it."

Perlozzo also said Fahey and Chris Gomez will see a lot of action in the middle infield. Baltimore won't lose much defensively, but offense may be a problem. Roberts is batting .330 and leading the team in stolen bases (nine), but Perlozzo said the Orioles have to worry about the big picture.

"I think he's pretty sore," he said. "He may feel a lot better in the next three days, but if we wait and he's not close to 100 percent, we're just playing with the chance that he might do something that will really cost us a huge chunk of time. We can't afford that with him."

Punching the clock: Fahey didn't have much time to think about his new gig. The infielder was yanked from a game for Triple-A Ottawa during the middle of an at-bat, and he was at the airport at 2:45 a.m. ET. He said he hadn't gotten much sleep, but he was still excited to be in Sunday's starting lineup.

"I still can't believe it," he said. "I'm shocked. I don't think it's hit me yet."

Fahey, the son of former big-league catcher Bill Fahey, said he was confused when he first got the call. There he was, in his helmet and batting gloves, preparing to get on base. The next thing he knew, he was on the sidelines, talking to his manager with his head racing a million miles an hour.

"I was about to hit -- in the batter's box and the pitcher was on the rubber," he said. "Our manager called me over and said, 'I need to talk to you.' He had just gotten the phone call to take me out of the game because something had happened.

"By the time he took me out of the game, it surprised the heck out of me."

Fahey was hitting .279 with a .402 on-base percentage for Ottawa, but he also made six errors in 20 games down there. Still, the 25-year-old really clinched his callup with some solid play in Spring Training.

Perlozzo noticed him then and ranked him high on the list of possible contingency plans.

"He's a roster guy that played well in the spring and can play shortstop. That's pretty much we needed," Perlozzo said. "Mr Fahey can possibly [lead off], but we didn't want to throw him into the fire."

Backed up: Lopez was pulled from Saturday's game with back spasms, but he said he's made some progress over the last 24 hours. The three-time All-Star said he's had a similar ailment just once before in his career.

"I thought I was going to be out for a while. I got treatment yesterday and woke up like nothing happened," he said. "I don't want to be too optimistic. I'm going to take batting practice and see how I feel."

The backstop also commented on Saturday's rash of injuries, which saw the Orioles make seven defensive substitutions in one inning.

"That was weird," he said. "I call it Black Saturday."

Quotable: "I just called my parents, my brother and my girlfriend -- told them. They got on a plane and they're here today." -- Fahey, on his first promotion to the parent club

Coming up: The Orioles will welcome the Blue Jays for a two-game set that starts on Monday, and Erik Bedard will pitch the series opener. The southpaw will be matched up against veteran Ted Lilly.