"They did a fluoro scan," he said. "They said it looked good. I'm moving it around a little better. They said maybe X-rays tomorrow if it's not looking good. But right now it seems like it's fine.
"Initially I thought it was bad."
Knapp tried throwing the ball a few times to first baseman Tommy Joseph, after Phillies manager Pete Mackanin and head athletic trainer Scott Sheridan examined the hand on the mound. They did not like what they saw and pulled Knapp from the game.
Cameron Rupp took Knapp's place behind the plate.
Knapp entered the game hitting .255 with three home runs, 12 RBIs and a .739 OPS in 187 plate appearances. If he needs to miss time, Triple-A catcher Jorge Alfaro is the only other catcher on the 40-man roster.
Alfaro, who is the No. 70 prospect in baseball in MLBPipeline.com's top 100 prospects rankings, is hitting .244 with seven homers, 43 RBIs and a .657 OPS. He has struck out 110 times and walked 16 times in 346 plate appearances.
Todd Zolecki has covered the Phillies since 2003, and for MLB.com since 2009. Follow him on Twitter and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.