BOSTON -- The A's on Tuesday made official what's been known for about a week, announcing that right-hander Sean Gallagher is the player to be named later in the July 5 trade the brought outfielder Scott Hairston to Oakland.

Gallagher, obtained in the Rich Harden trade with the Chicago Cubs on July 8, 2008, was 1-2 with an 8.16 ERA in six games (two starts) during two stints with Oakland this season. He was optioned to Triple-A Sacramento on April 23 and then again May 19.

A 23-year-old Boston native, Gallagher posted a 1-0 mark and a 1.74 ERA in five starts for Sacramento before being placed on the disabled list June 12 with a strained left knee.

The Padres also received Minor League pitchers Ryan Webb and Craig Italiano in the four-player trade.