PHILADELPHIA -- Infielder Chad Tracy, who was fighting for a roster spot in Spring Training after signing a Minor League contract with the Nationals during the offseason, has agreed to an extension with the team through the 2013 season.

Tracy, whose road back to the Majors has not been easy after spending the 2011 season playing in Japan, said he felt things have come "full circle" with the opportunity to rejoin the club again next year.

"Last couple years, two or three years, in the offseason, I didn't know what was going to happen," Tracy said. "In 2003, I was signing Minor League deals and having to come in and fight in Spring Training to make a club. To have a guaranteed year and know where you're going next year for your family, you can kind of start planning. It's great. It's a good way to play."

Tracy has appeared in 43 games this season for Washington -- his first, after spending six years with the D-backs, and one with each the Cubs and Marlins -- and has been a valuable left-handed bat off the bench.

"I think it's a story of perseverance and love of the game," general manager Mike Rizzo said. "He had an injury-plagued season last year, went to Japan. Your comfort level is really tested there. Your love of the game is tested. And to compound that with being injured, it really made it difficult for us.

"So when we talked to Chad this offseason and his agent, we felt we had a good enough relationship that we made promises he would get an opportunity to make the club. And his performance allowed for him to make the club. And he just kept exceeding expectations and played extremely well. He's a real asset on the club."

Tracy has hit .283 -- which would be his highest season batting average since he hit .308 in 145 games with the D-backs in 2005, his second season -- with three homers and 13 RBIs. Ten of his 13 RBIs have come in pinch-hit situations, in which he is batting .320 with a .400 on-base percentage and .920 OPS.

"You had two parties that wanted to be together," Rizzo said. "He's been a great teammate and he's been great off the bench. We thought it was a good time to lock him up so he didn't get to free agency and test the waters. We know we have a guy we like, and a guy that's performed for us. So we felt it was a good time to lock him up for next year."

Both Rizzo and manager Davey Johnson pointed to former National Laynce Nix as a valuable role player who had an strong season, tested the free agent waters and signed a two-year extension elsewhere. Rather than taking that risk with Tracy, the Nationals nipped it in the bud.

"I think this goes kind of hand in hand with some history of some talented role players," Johnson said. "Like the perfect example here with Nixy. He got a two-year contract to come over [to Philadelphia] and we were going to offer him a one-year deal. So rather than get caught with our pants on fire, [we signed Tracy to an extension]."

Rizzo said it can be considered a good sign that the team is working to lock up key bench pieces, while Tracy said the opportunity to come back with a club that carries such promise did factor into the decision.

"You're on a first-place team over 30 games over .500, and they're offering you an extension," Tracy said. "There's really not a whole lot better than that."

Desmond may miss series; Suzuki returns

PHILADELPHIA -- The Nationals held shortstop Ian Desmond out of Friday's series opener against the Phillies with a mild strain of his right hamstring, and the All-Star could miss the entire series in Philadelphia this weekend.

Desmond was a late scratch, for precautionary reasons after he apparently tweaked his right knee in Wednesday's loss to the Braves. The Nationals said he could have pinch-hit, if needed.

"The pain is a little bit up his hamstring," manager Davey Johnson said. "I wasn't going to use him to pinch-hit and aggravate that and have a bigger problem."

Desmond went through warmups Friday, and said he didn't aggravate the injury. But with a day off Thursday and another Monday after the three-game series in Philadelphia, the first-place Nats wanted to play it safe.

"It was more of a direct thing today," Desmond said. "I just feel it in my hamstring a little. I guess the doctor diagnosed it as a mild strain. I'm sure it's something I've had before and not even known. Just a little bit sore. I think Davey just wanted to be smart and see if we can get better in the next few days and take care of it before it gets any worse."

Danny Espinosa moved from second base to shortstop, and Steve Lombardozzi was inserted into the leadoff spot and played second base. Jayson Werth was moved to the sixth spot in the lineup, where Desmond was originally slotted.

The Nationals were also without left fielder Michael Morse for most of the game, after he was hit by a pitch on the right hand in the first inning, and the offense managed just six hits in the 4-2 loss.

"At the end of the day, we're comfortable with anybody we put on the field regardless of what happens," said starting pitcher Edwin Jackson, who took the loss. "It's not as if a starter goes out and someone off the bench has to go in, that we lose confidence. These are guys who have been doing it all year -- whether it's been Mikey Morse or Desmond gone, everybody just comes in to step up."

Catcher Kurt Suzuki was back in the starting lineup Friday after taking a foul tip Wednesday directly off the back of his right hand. X-rays taken after the game were negative.

"Suzuki, I thought had a broken hand," Johnson said. "He's fine, too."

Top pick Giolito to undergo Tommy John surgery

PHILADELPHIA -- Nationals general manager Mike Rizzo said the impending Tommy John surgery for top pick Lucas Giolito did not necessarily come as a surprise, and that the club remains confident in the 18-year-old right-hander's promise after he rehabilitates.

Giolito appeared in just one game for the Gulf Coast League Nationals, tossing two innings -- allowing one run and two hits while striking out one -- before feeling some pain.

"After we drafted him, we were well aware of the possibilities of the elbow injury and we tried to test the waters and have him throw in Instructional League rehab and let it loose and see where we were at," Rizzo said. "He did it and he felt some pain, so we had him checked out by our doctor. They saw that he had a complete tear of the ulnar collateral ligament. We got a second opinion from [Dr. Lewis Yocum] and he seconded the diagnosis of our team doctor and he scheduled him to have the surgery at the end of August."

Rizzo believes Giolito -- the Nats' first-round pick in the 2012 First-Year Player Draft out of Harvard-Westlake High School in Los Angeles -- was comforted by the Nationals' history of successfully rehabbing pitchers from Tommy John surgery, including Stephen Strasburg and Jordan Zimmermann.

"I think he feels relieved that he's with the Washington Nationals," Rizzo said. "I think he'd be at UCLA if we weren't the team that drafted him. He knows that we care about our players, he knows that we're going to get this fixed and rehab him and he feels very confident he's going to bounce back and pitch in Washington real soon."