Manager Mike Scioscia said the magnetic resonance imaging (MRI) done on the oblique, which is near the hip, showed that the injury will need time to heal.
"We've got a window of about six weeks right now to where he can be back with us," Scioscia said.
Bootcheck said he's heard all sorts of numbers, in part because his recovery time will depend on how quickly his body heals itself.
"I've heard anywhere from four to six [weeks], six to eight," Bootcheck said. "The doctor said within four to 10 days, they'll know a lot about timeframes for throwing off a mound and all that."
Bootcheck said the injury already felt significantly better than it did on Sunday, when it was suffered during a Cactus League game. Both he and Scioscia said they were glad the injury occurred in spring rather than during the season, when it would cost him more Major League games.
"I'd rather miss a week than three months," he said. "This is one of these things where your body will tell you when you're ready to go."
Adenhart tagged: Nick Adenhart had a rough start Wednesday, yielding seven hits and five runs in 2 2/3 innings. He did, however, make some good pitches to limit the damage.
"I made some good pitches late in some innings," Adenhart said. "I fell behind of some guys, got in some tough counts. It's definitely the biggest test I've faced so far, or the best lineup, the most big league lineup."
Scioscia liked what he saw from Adenhart, for the most part.
"He fell behind too many hitters today, but he showed the stuff that we're all excited about, and as the game went on, he was much better," Scioscia said.
Adenhart said he knows what he needs to do to improve on Wednesday's results.
"Fastball command needs to be better," Adenhart said. "My offspeed stuff is where it needs to be. The consistency of it has gotten a lot better over the last couple years."
Kendrick on the move: Second baseman Howie Kendrick is primed to run more this season, and Scioscia believes Kendrick has the ability to be a factor on the basepaths.
"Howie certainly has the ability to steal between 20 and 30 bases a year," he said.
The question with Kendrick will be his experience, as Scioscia believes successful basestealing has a lot to do with understanding the pitchers, catchers and team philosophies around the league.
Kendrick stole only five bases in nine attempts last year, but stole between eight and 25 bases in each of his Minor League seasons. He was 2-for-3 with a run and an RBI Wednesday.
Torii takeoff? Scioscia also discussed whether Torii Hunter would use his good speed to steal bases or not. While he's a strong runner, Hunter's stolen-base totals have fluctuated. Going back through the past seven seasons, he's stolen 18, 12, 23, 21, 6, 23 and 9 bases.
"Torii has the ability to be very aggressive, but it's really going to be contingent on how much the other team tries to stop the running game," Scioscia said.
Regardless of his steal totals, Scioscia said he expected Hunter to excel at other facets of baserunning, such as going from first to third on a single. Wednesday, Hunter doubled and scored and tripled in scored while going 2-for-3.
Some value in spring: Spring Training isn't really about wins and losses, but that doesn't mean the Angels weren't paying close attention to the Mariners Wednesday.
"There's a lot of scouting that goes on," Scioscia said. "We're looking at anything they're putting out there as far as tendencies."
Up next: The Angels will host the Giants on Thursday at 12:05 p.m. PT. Jered Weaver will open for the Halos, while Matt Cain will throw for San Francisco.
Mark Thoma is a contributor to MLB.com This story was not subject to the approval of Major League Baseball or its clubs.