A's place Dallas Braden on DL
Braden left Saturday's game after five innings with shoulder stiffness. He is 1-1 with a 3.00 ERA in three starts this season, a year after pitching a perfect game against the Tampa Bay Rays.
Harden has been out with a strained right shoulder since spring training. He was originally put on the 15-day DL retroactive to March 22.
The A's also announced Monday they acquired left-hander David Purcey from Toronto for minor league right-hander Danny Farquhar.
Farquhar was traded from Toronto to Oakland in November.
Copyright 2011 by The Associated Press
MORE MLB HEADLINES
- Hamels slated to make season debut in L.A.
- Stanton's walk-off GS lifts Marlins over M's
- Pujols belts No. 497 in Angels' rout of Tigers
- Mets trade 1B Davis to Pirates for reliever
MOST SENT STORIES ON ESPN.COM
- FANMATS Oakland Athletics Heavy Duty Vinyl Car Mats 2-Pack