That was a sentiment shared by manager Ron Washington.
"We've just got to wait and see how it comes out," Washington said. "He said he felt a pop."
McCarthy said the injury happened when he tried throwing a slider, but said it actually occurred during his windup and not during his delivery. Afterward, the finger began to swell up on him.
This latest injury for McCarthy comes less than a month after he made his first Major League start of the season on Aug. 23 after being shut down for most of the season with severe inflammation in his right forearm.
"This one is pretty frustrating," McCarthy said. "Coming in, I thought I was doing the things I needed to do mechanically. I felt like it was going to be a good day."
It began as a good day when McCarthy induced back-to-back flyouts to begin the game, but he got to a 1-1 count on Magglio Ordonez and quickly called catcher Taylor Teagarden out to the mound.
Before long, nine observers were surrounding McCarthy to see what was wrong. McCarthy was taken out of the game then and there and now even Washington isn't sure when he may pitch again.
"We certainly want to see him pitch out there," Washington said. "We just have to keep moving forward."
But even with McCarthy having suffered two injuries in the same season, Washington isn't ruling out his chances of being a durable pitcher for the Rangers someday.
"I don't have the knowledge or experience to talk about his durability," Washington said. "That was a freak thing that happened tonight."
Shawn Shroyer is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.