Right-hander Rich Harden is making the perfect case for turning the Oakland Athletics' Big Three into the Big Four.

Harden, who retired all 39 batters he faced in two starts for Double-A Midland of the Texas League, has been moved up to Triple-A Sacramento, the Contra Costa Times reported.

A's manager Ken Macha told the newspaper that Harden won't be rushed, but it is possible he could be called up later this season and possibly join Barry Zito, Tim Hudson, and Mark Mulder in the A's rotation.

On Tuesday night, Harden pitched seven more perfect innings and struck out eight as Midland defeated Round Rock 4-1. Overall, Harden retired 17 of the 39 by strikeout.

Harden had been scheduled to pitch against Round Rock again Sunday afternoon.

In Midland's season opener last Thursday against Round Rock, Harden pitched six perfect innings in a 5-0 victory. He was pulled early from the games presumably because of predetermined pitch counts.

Only two perfect nine-inning games have been pitched in the Texas League. Consecutive perfect innings are not recorded by league statisticians.

Harden, a hard-throwing 21-year-old from Victoria, British Columbia, has been watched by a host of scouts in both of his starts. The A's selected him in the 17th round of the 2000 free-agent draft.