Nationals reliever Stammen needs forearm surgery

WASHINGTON (AP) Washington Nationals reliever Craig Stammen has a torn flexor tendon in his right forearm that requires surgery and could force him to miss the rest of the season.

Manager Matt Williams gave the new Thursday after Stammen had an MRI. The operation has not yet been scheduled.

''Depends on the extent of the damage,'' Williams said of Stammen's chance of missing the season.

The 31-year old right-hander appeared in five games - all in relief - without allowing a run in four innings. He went on the disabled list Wednesday.

''It's never good news,'' Williams said of the surgery. ''But knowing him, he'll rehab as quick as he can, as hard as he can, and be back at some point. We just don't know the time frame.''

Also, the Nationals recalled left-hander Felipe Rivero from Triple-A Syracuse and optioned righty Taylor Jordan to their top farm club.

Rivero, 23, will be making his major league debut.

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