Callaspo joins first-place A's from Angels

About 14 hours after he learned he'd been traded by the Angels while playing in Texas, infielder Alberto Callaspo joined his new Oakland team confident he can still play his old second base position.

The AL West-leading Athletics acquired Callaspo late Tuesday to give them infield depth, then he hopped an early flight out of Dallas in time to be available for the finale of Oakland's three-game series with Toronto on Wednesday afternoon.

Callaspo left Los Angeles' game with the Rangers after the fourth inning.

''I was kind of surprised they took me out in the fourth or fifth inning,'' he said. ''I came here and I will keep doing my job 100 percent and trying to help the team. It's good. I've played with some of the guys here and it's going to be fun, it's going to be nice.''

To clear roster room, the A's designated infielder Adam Rosales for assignment with the hope they can hold onto him because he is the club's top defender at the shortstop position. Manager Bob Melvin said Callaspo could be used in a platoon at second with Eric Sogard and also spell third baseman Josh Donaldson when he needs a break.

Third base coach Mike Gallego hit grounders to Callaspo at second base for his first fielding work since 2010.

''Whew, long time,'' Callaspo said before the workout. ''Yeah, I can do it. I signed at second base. ... I can play everywhere but not catcher and not pitcher.''

He is batting .252 with five home runs and 36 RBIs in 86 games this season but is just 4 for 36 in 12 games since the All-Star break.

Melvin had Callaspo on his Arizona team in 2006-07.

''We're happy about having him, and it's probably a good thing we have an off day tomorrow so he can get acclimated a little bit as far as living situation,'' Melvin said. ''He's a pretty unique player. He started out as a second baseman and he's athletic and talented enough to be an everyday third baseman. He can play just anywhere, switch-hitter, good from both sides of the plate. I think one of the most difficult guys in baseball to strike out, you can hit and run with him, there are a lot of things you can do with him. It is an upgrade for us.''

The A's traded Triple-A infielder Grant Green to the Angels.