ANAHEIM -- Catcher Mike Napoli, who has been on the disabled list since July 6 with irritation in his right shoulder, is expected to be activated Friday before the Angels open a three-game series with the Yankees at Angel Stadium.

Napoli has made four rehab starts with Class A Rancho Cucamonga, including Tuesday night when he went 1-for-4 with a double. Napoli has hit .500 with one home run and three RBIs in 10 at-bats with the Quakes. Napoli also threw out two runners attempting to steal on Tuesday, which means his injured shoulder is responding well.

"He threw the ball great," Angels manager Mike Scioscia said. "We got a great report on his catching, and he's going to catch again tonight, and if everything goes well, he'll be activated Friday."

In Napoli's absence, Jeff Mathis has taken the brunt of the workload behind the plate, starting 26 of the past 27 games for the Angels, including Wednesday's game against the Orioles. Mathis has hit .205 with three homers and 17 RBIs in that span.

Mathis understands that his workload will decrease once Napoli is activated but has mixed emotions about not starting every day.

"I love playing every day," Mathis said. "So it kind of works both ways. It'll be nice to get some rest, and you never know how it will be when he comes back. I'm not sure if we'll be splitting it up like we were, but I'm just happy to have him back."

Scioscia previously played the hot hand at catcher and would pick who to play based on how they matched up with the opposing starter. It's still unclear how the rotation will work when Napoli gets back, but the two catchers are best friends and roommates off the field, so they take their playing time in stride.

After talking to Napoli last night, Mathis expects his fellow catcher to return for the Yankees series.

"He said everything's feeling good," Mathis said. "He should be on track."

Napoli was batting .204 with 12 homers and 29 RBIs in 47 games before his injury.