Nationals' Drew Storen breaks right thumb in frustration after giving up Yoenis Cespedes home run

WASHINGTON -- The stumbling Washington Nationals are now hurting themselves.

Right-hander Drew Storen broke his right thumb slamming the lock box in his locker in frustration Wednesday after giving up the go-ahead homer to Yoenis Cespedes in the eighth inning, helping the NL East-leading New York Mets complete a three-game sweep.

Nationals manager Matt Williams said Saturday the former closer would likely miss the rest of the season.

Washington didn't learn of the injury until Storen was unable to throw Friday in Miami. The reliever then told the team what happened, and an X-ray revealed the extent of the injury, Williams said.

Storen flew back to Washington on Saturday to be examined by a hand specialist.

The reliever's reaction to the injury?

"Regretful that it happened," Williams said, "and a little bit embarrassed about it, of course. He's a competitor, and he was frustrated and made a mistake."

Like his teammates, Storen has struggled lately. He walked three batters Tuesday when the Nationals blew a six-run lead against the Mets, who padded their cushion in the NL East with the sweep.

Storen is 2-2 with a 3.44 ERA in 58 games.

"He's a big guy lost for us, so some other guys will have to step in and do that job," Williams said. "It gets guys in some different roles for sure."