"Fields is being evaluated every day," Hinch said. "He's getting treatment. He'll play catch and keep his arm in shape a little bit. He won't throw off the mound for a few days. He's going to keep his arm in shape as much as he can without testing his groin."
Hinch said the Astros wouldn't have a need to be concerned about Fields' availability for the start of the regular season until early next week if he's still down.
Meanwhile, two other Astros pitchers are on the mend. Right-hander Brad Peacock, who's building up his pitch count after having hip surgery in October, could make his Grapefruit League debut this weekend, mostly likely Sunday against the Yankees.
Left-hander Brett Oberholtzer, who hasn't pitched since March 10 because of a lat strain and later an illness, was scheduled to throw in a Minor League game Wednesday in Kissimmee. He was expected to stretch out to 30 or 40 pitches. He's penciled in as the No. 4 starter.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.