OAKLAND, Calif. — Nomar Garciaparra is back on the Oakland Athletics' disabled list with the same calf injury that already sidelined him for three weeks.

The A's activated Garciaparra from his first DL stint Friday only to see him start two games at first base against the Arizona Diamondbacks then go back on the disabled list Wednesday. Garciaparra went 3-for-9 with a home run in those games. The move is retroactive to Sunday.

"Nomar was unable to go last night," manager Bob Geren said. "This is the best course of action, to get him ready in 12 days. Being that he didn't really totally re-injure it, chances are a lot better for a speedy return."

Garciaparra, who turns 36 on July 23, is on the DL for the 14th time in his career and fifth in two seasons. He missed 90 games for the Los Angeles Dodgers last season and needed three DL stints with injuries to his right hand, left calf and left knee.

Garciaparra will stay in the Bay Area to rehab during the team's upcoming seven-game road trip to Texas and Chicago and could play in some minor league games.

"We left it up to how he feels," Geren said.

Oakland recalled right-handed reliever Jeff Gray from Triple-A Sacramento to fill the roster spot. Gray was also with the A's from May 9-13 and made one appearance.

The A's have used the DL nine times already this season after setting an Oakland record with 25 DL trips in 2008.

With Garciaparra shelved again, outfielder Travis Buck is getting some groundball work at first base in case he's needed there. Buck also played some third during college at Arizona State.

"He seemed to pick it up pretty quick," Geren said of Buck being back in the infield. "The finer points around the bag is what he feels he needs the most improvement on. ... I think he could do it right now if he had to."