Manager Joe Torre said the tests, conducted after Kuo experienced a "weird" feeling in his fingers warming up during Saturday's game, were negative. But Kuo will have further testing in Los Angeles this week "to make sure everything checks out," according to Torre.
If it does, Torre said, Kuo will be sent to the instructional league in Arizona to resume a pitching routine for possible inclusion on the roster for a potential later round.
Kuo, who has had four operations on the elbow (including two Tommy John ligament reconstructions) said the sensation in his fingers did not leave immediately and that he was nervous when he took the test Saturday night.
"I had never seen that machine before," he said.
Kuo had pitched only once in the last three weeks after developing day-after stiffness in the triceps tendon area. An MRI revealed no structural damage and the injury was believed to be a bone bruise. He's been playing catch all week, but said when he throws hard, he's felt the stiffness the following day. This was the first time he had reported an unusual sensation in his fingers.
Torre has not named his postseason pitching staff beyond starters Derek Lowe, Chad Billingsley and Hiroki Kuroda. But doubting Kuo's availability, he previously said he would take an 11-man pitching staff.
The most likely remaining eight are Takashi Saito, Jonathan Broxton, Joe Beimel, Cory Wade, Chan Ho Park, Scott Proctor, Greg Maddux and Clayton Kershaw. However, rookie James McDonald is still in the mix and could sneak onto the roster as a long reliever.
Torre has not said whether Lowe would pitch Game 4 on three days' rest or if that start would go to the 42-year-old Maddux or the 20-year-old Kershaw.
Torre said the club will also send to the instructional league pitchers Ramon Troncoso and Scott Elbert, infielder Chin-lung Hu and outfielder Jason Repko. The purpose will be to have them game-ready and available to be added to the roster for a later round. Submitted rosters cannot be changed during a series, but can be changed between series. Eric Stults will not travel with the club but will pitch winter ball. Jason Johnson was told he won't be on the postseason roster and went home.
A.J. Ellis will travel with the club in the event an emergency catcher is needed. Three more roster moves will be needed to reach 25.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.