A's right-hander Sonny Gray has a moderate lat strain and will not throw for three weeks.
The injury likely means that Gray will not be Oakland's Opening Day starter for a second straight season. He was a late scratch in 2016 because of food poisoning.
Gray, 27, has allowed seven runs on six hits and four walks in four innings over two Cactus Leagues starts after experiencing an injury-plagued 2016.
Cash Kruth is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.