The Padres obtained right-handed pitcher Sean Gallagher from the A's on Tuesday to complete the July 5 trade that sent outfielder Scott Hairston to Oakland.
In addition, the Padres activated second baseman David Eckstein and catcher Henry Blanco from the 15-day disabled list. Both players have been out since well before the All-Star break with hamstring injuries.
Gallagher, 23, was highly rated by the A's, who picked him up last year from the Cubs in the six-player deal that sent pitchers Rich Harden and Chad Gaudin to Chicago. But Gallagher never developed this season, spending two periods with the A's sandwiched around a demotion to Triple-A Sacramento.
Gallagher made six appearances and two starts for Oakland, going 1-2 with an 8.16 ERA.
Eckstein sustained what Padres manager Bud Black said was a first-degree strain of his right hamstring while trying to leg out a ground ball during the bottom of the 12th inning of a 7-6 loss to the Dodgers at PETCO Park on July 5. The infielder was placed on the DL the next day. Eckstein has played in 80 games for San Diego this season, hitting .267 with 15 doubles, a triple, a home run, 33 RBIs and 30 runs scored.
Blanco also strained his right hamstring running the bases in a 7-4 home victory over the Dodgers on July 4. The catcher has been on the DL since July 5. He's hit .218 with five doubles, four homers, 10 RBIs and 14 runs scored in 38 games.
Barry M. Bloom is a national reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.