The Nats officially placed Werth on the 15-day disabled list today, retroactive to May 3, and called outfielder Eury Perez up from Triple-A Syracuse.
Werth is batting .260 with four homers, 10 RBIs and 17 runs in 27 games this season. He'll be eligible to return on May 18.
This will be the second stint in the big leagues for the 22-year-old Perez, who earned a September callup last year. Perez was ranked the Nats' seventh-best prospect by Baseball America over the winter.
He was hitting .346 with five doubles, a triple, a home run, six RBIs, seven stolen bases and 17 runs in 23 games with Syracuse. Perez was doing especially well lately, batting .381 with three steals and nine runs during a nine-game hitting streak leading up to the roster move.
Update: Forgive Perez if he's a little tired today; he made the seven-hour drive from Syracuse to D.C. last night. After getting a decent night's sleep, he got to Nationals Park this morning and received a warm welcome from the guys in the Nats clubhouse.
Perez will serve primarily as outfield depth on the Nats' bench during his tenure here. The Nationals needed another right-handed hitting outfielder with Werth going on the DL, and while they considered bringing up Jeff Kobernus from Syracuse, it was Perez who got the call.
The Nationals went with Perez for a couple of reasons: he's on the 40-man roster, while Kobernus isn't, and Perez is a career outfielder, while Kobernus has been an infielder up until this season, when he started getting some time in the outfield.
"He's a complete player, I really like all his talent," manager Davey Johnson said of Perez. "Good defensively, good at throwing to bases, he can bunt, he can hit to all fields. He knows his strike zone better. I think he's going to be much better served (this time). I thought last year, at times, he felt a little out over his skiis, and that's inexperience. I think he's going to feel more comfortable being here."
Meanwhile, Johnson said that the Nats' trainers and doctors continue to be perplexed by Werth's hamstring, which has seemed close to full health a couple of times only to then start cramping again. The Nats hope that Werth will be able to return to the active roster when he's eligible to come off the DL on May 18.
Werth eats a gluten-free diet, which Johnson joked might be playing a factor in the recent health issues.
"Well maybe he needs a little wheat," Johnson said with a smile. "I might need to slip him some wheat. Is he either going to keel over and die or is he going to get well?"
Only one way to find out.