"It is sore to a point that I can't really do real damage out there to help the team win," Rodriguez said Saturday before the Yankees' 6-0 loss to the Los Angeles Angels on Saturday night.
After Friday night's game, Rodriguez told Yankees manager Joe Girardi his thumb was still irritating him. Rodriguez previously missed six games with the thumb problem.
"Sometimes nagging injuries are hard to get rid of," Girardi said.
Rodriguez has played only 10 games in the second half of the season because of his knee surgery during the All-Star break. During the first game back from the operation, on Aug. 21 in Minnesota, he rolled over his glove on a Joe Mauer grounder. Rodriguez has a .194 average, two homers and four RBIs in the 10 games.
"I can play with bumps and bruises," Rodriguez said. "Even with bumps and bruises I can do serious damage, but with the way I am right now, I don't think it is possible."
The Yankees received better news on right fielder Nick Swisher. Swisher is day-to-day after an MRI on his left elbow showed no structural damage, just inflammation.
"Anytime you are going for an MRI, you never know," Swisher said. "I've never really had pain in my elbow. It is a bummer because you know right now you want to be in there."
Cervelli is headed back to New York to have further examinations for a possible concussion, which would be the third he's suffered in his career.
"I think I need to rest for a couple of days," Cervelli said. "I'll see what the doctors say."
The Yankees are so banged up that rookie Eduardo Nunez started in right. He had played one inning all season there. He never played the position in the minors, he said.
With less than 20 games to go, Rodriguez feels this is the best time for him to rest the thumb.
"The time is now," Rodriguez said. "I think this is the only window we have to rest it and then strap it on and go."
On the season, Rodriguez is hitting .294 with 15 homers and 56 RBIs in 90 games. Rodriguez is on pace to fail to hit 30 homers for the first time since 1997.
Andrew Marchand covers the Yankees for ESPNNewYork.com.