OAKLAND, CALIF. ? The Oakland Athletics recalled right-handed pitcher Kirk Saarloos from Triple-A Sacramento on Sunday to add depth to their overworked bullpen and to make a spot start this week.

To make room for Saarloos, the A’s optioned infielder Ramon Castro to Sacramento.

When Tim Hudson went on the disabled list Saturday, Oakland had considered starting Saarloos on Sunday against the San Francisco Giants. Then, Mark Redman volunteered to pitch on three days’ rest, so Saarloos was in the bullpen Sunday.

Right-hander Justin Duchscherer wasn’t available to relieve after pitching 3 1/3 innings Saturday after Rich Harden got hurt. Setup man Arthur Rhodes hasn’t been available since Wednesday because of spasms in the middle of his back.

Saarloos will start either Thursday, Friday or Saturday.

Harden’s turn to pitch is Thursday, but the right-hander may not be able to make his start after partially dislocating his non-throwing shoulder Saturday in the third inning while trying to cover first base.