ATLANTA -- Nationals outfielder Austin Kearns appears to be on pace for his return from a right thumb injury, meaning he could be back in action in the next couple of weeks.

Kearns has been on the 15-day disabled list since Aug. 4 with a deep thumb bruise. He had surgery on the thumb on Friday, but Nationals interim manager Jim Riggleman thinks Kearns could be back shortly after his stint on the DL is over.

"I don't think it will be too much past his DL time," Riggleman said. "We should be able to get him swinging again and get him activated. They are working on closing the sutures now."

Kearns was hitting .195 with three home runs before going on the DL.

In other Nationals injury news, right-hander Jordan Zimmermann had the original diagnosis of the injury to his pitching elbow, a torn ulnar collateral ligament, confirmed in Los Angeles by Dr. Lewis Yocum.

Zimmermann will have Tommy John reconstructive surgery on Aug. 19, and will rehab in Washington afterward.

"He understands what's going on," Nationals acting general manager Mike Rizzo said. "He has talked to some guys that have been through it. He's as upbeat as he could possibly be about it."