2:44pm: Roch Kubatko of MASN.com reports that it's official; the O's announced they've released Walker.
1:55pm: Jeff Zrebiec of the Baltimore Sun reports that the Orioles will release lefty reliever Jamie Walker. Baltimore still owes Walker about $3MM, but they were no longer satisfied with his production. To replace Walker, they called up Alberto Castillo, another lefty who pitched for the O's last year and has performed well at Triple A Norfolk so far in 2009.
Zrebiec writes that the move is "not all that surprising" because lefties are hitting .458 against Walker this year. The pitcher signed a three year deal worth $12MM before the 2007 season.