On Monday, Weiss said it was doubtful that Rosario could swing a bat, but he could be used in a pinch as a defensive replacement. That changed a bit on Tuesday.
"Today, he's swung the bat. He hasn't taken batting practice or anything, but he's taken some dry swings," Weiss said. "He's getting better."
When asked whether Rosario would be able to hit in the game, Weiss said, "He'd have to if we put him in there to catch. Yeah, he's OK. He's available to use in the game if we need him."
Rosario injured the hand swinging the bat this past weekend in Los Angeles. He's batting .244 with three homers and 13 RBIs in 22 games.
Charlie Culberson remains Weiss' emergency option behind the plate.
Barry M. Bloom is national reporter for MLB.com and writes an MLBlog, Boomskie on Baseball. Follow @boomskie on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.