ANAHEIM -- With his freshly healed left ankle allowing him the proper leverage to attempt a base theft, catcher Mike Napoli took off for second base and dropped to the dirt with a textbook feet-first slide. The beneficiary of a newly stolen bag, Napoli attempted to stand, but found that he had acquired something extra, something unexpected and wholly unwanted -- a strained right hamstring.

Only one week after returning to the lineup since suffering a home-plate collision that sprained his ankle on July 1, Napoli found himself back on the disabled list. The hamstring strain occurred in the first inning of the Detroit series opener Friday. A July 20 contest at Minnesota marked his first post-ankle sprain appearance.

"Mike's pretty sore today," Angels manager Mike Scioscia said. "We're going to take every precaution right now to where he can get back to be 100 percent."

Jeff Mathis will take over for Napoli in the interim, while Triple-A Salt Lake callup Ryan Budde will take Napoli's place on the 25-man roster.

With the recent departure of seasoned catcher Jose Molina, the Angels must rely on a pair of relatively untested receivers to man the post behind the plate. But Scioscia is not worried.

"I don't think you would've seen Jose being traded if we thought we didn't have guys that could really bring the pieces we need in the organization," Scioscia said. "We feel very confident in that."

Mathis, the organization's three-time Defensive Player of the Year, has started six games since his arrival on July 2. Aside from an occasional bout with dropped balls, Mathis has provided fairly solid relief for Napoli.

Mathis' struggles at the plate -- he holds an .095 average through 21 at-bats with two hits, an RBI and eight strikeouts -- remain a more pertinent question mark, however.

But the pressure to perform has yet to rattle his resolve.

"I'm a lot more relaxed," Mathis said. "I try not to think about pressure. I try not to let it bother me. I used to put a lot of weight on my shoulders, but I just want to do well and help my team out."

Although his time fielding big-league pitches has been limited, Mathis maintains that he is very comfortable with the starting rotation, which has helped alleviate some of the weight he once shouldered.

"I've been with a lot of those guys for a couple years [in Spring Training]," he said. "It's a great organization. It's fun to catch."

Budde, a "terrific catch-and-throw" guy, according to Scioscia, likely will split time with Mathis. Not one to "put all your eggs in the experience basket," Scioscia believes that the inexperience of Mathis and Budde will be remedied by their raw talent.

"There are two ways to get production," Scioscia said. "It's either going to be with experience, or it's going to be with talent. Some guys are going to have less experience and play at a higher level because of their ability. Some guys with experience don't have talent to really match some of that.

"These kids are untested, but we're very confident in seeing the way they handle themselves and the way they work in a big-league camp."

While the pair continues to make adjustments, familiarizing themselves with each pitcher's every tendency and nuance, the game plans will be simplified.

"It'll probably be managed more by the pitcher in the early going, but doesn't mean the catcher isn't going to take over at some point," Scioscia said.

Santana making strides: Recently demoted Ervin Santana tossed 6 1/3 innings for Salt Lake on Friday, allowing six runs on 11 hits in a 13-7 win over the Omaha Royals. He walked two and struck out four.

"His stuff was good," Scioscia said. "It got elevated a little as the game went on. He pitched well through six; the seventh he had a little bit of a problem. The line score wasn't good, but the stuff was good, and that's still, right now, more important."

A timetable for the talented right-hander's return has not been set.

"I don't think there's any definite number," Scioscia said. "As long as we see him moving forward, which we feel he is, I think they'll come a point where he's ready for this challenge again."

New addition: Shannon Ebel, the wife of Angels third-base coach Dino, gave birth to the couple's second child on Wednesday. Brady Alex Ebel was born at 10:45 p.m. in Las Vegas, weighing 7 pounds, 8 ounces.

On this day in Angels history: In 1964, Jim Fregosi recorded the first cycle in club history during a 3-1 win at New York. Exactly 40 years later, Troy Percival became the 18th player in Major League history to record 300 saves (he was the fifth fastest to do so) during a 2-0 win over Texas.

On deck: Dustin Moseley (4-1, 4.06 ERA) trades the bullpen for a return to the starting rotation when he faces Detroit's Jeremy Bonderman (10-2, 3.69 ERA) in the finale of a three-game set Sunday at 5:05 p.m. PT.