"He started to cramp up a little bit and had to step away from that bullpen session," Weiss said. "I don't know if I'd call it a setback, but I think once he felt a little cramping, we got cautious.
"It's not a sure thing, but I still have a feeling he's going to play sometime in L.A."
Rosario is hitting .292 with 29 homers, 22 doubles and 79 RBIs in his sophomore campaign, among the best totals for National League catchers and similar to numbers he posted in a breakout rookie campaign. He's also made strides defensively, as he was scrutinized for the 21 passed balls and 13 errors he finished with in 2012.
The Rockies play their final three games against the Dodgers starting on Friday.
Ian McCue is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.