Pine tar was found in Donnelly's glove during a June 14 game against the Washington Nationals. During the incident, Washington Manager Frank Robinson requested that the umpires check Donnelly's glove before he threw a pitch in the seventh inning.
Umpires found the pine tar on the glove, in violation of rule 8.02b, which prohibits a pitcher from having a foreign substance on his person or equipment.
On the team's Web site, the Angels said Donnelly cannot be replaced on the roster and they will have to go with 24 players, but will make a move to maintain their pitching staff at 11.
Orlando Cabrera, who has a right elbow strain, likely will be placed on the disabled list.
Donnelly (6-2) last appeared June 29, when he tossed two scoreless innings against Texas.