WASHINGTON -- Nationals manager Jim Riggleman filled out Tuesday's lineup card with Rick Ankiel in center field and Roger Bernadina receiving a precautionary day off.

But Bernadina replaced Ankiel, who exited in the second inning with a strained left intercostal (rib cage) muscle. Bernadina had two hits in three at-bats as the Nationals rallied to beat the Cardinals, 8-6.

Ankiel, who was listed as day to day, caught a routine fly ball from Cardinals third baseman Daniel Descalso for the third out of the second inning at Nationals Park but did not bat in the bottom of the inning. Bernadina singled against left-hander Jaime Garcia and remained in the game in center field.

"When he caught that ball in center field he just did something odd," Riggleman said. "He came back in and tried to swing the bat a little bit, and he said it really aggravated him. He just didn't feel he could let it go with the bat and if he did, he would really injure it. I won't play him tomorrow and then we'll see from there."

Ankiel spent time on the disabled list earlier this season after injuring his right wrist while making a diving catch.

LaRoche out for season with torn labrum

WASHINGTON -- Adam LaRoche resumed baseball activities this week after two weeks of completely shutting down. Still in pain from a labrum tear in his left shoulder, LaRoche learned on Tuesday he will be shut down for the season after surgery Thursday.

Nationals medical director Dr. Wiemi Douoguih will perform the surgery in Washington, where LaRoche will then rehab while remaining around the team. LaRoche, Douoguih and general manager Mike Rizzo all share the same goal: return healthy for next year's Spring Training.

"In the spring, it hurt to throw, but I could live with that if it didn't affect my swing. I didn't mind going the whole year with it being painful to throw. It started out OK, and it started affecting me at the plate," LaRoche said. "That's when you have to weigh it. Am I really helping this team out going out there at 50 or 60 percent and battling an injury? It wasn't worth it to me. I just don't want it to get to a point where it cuts into next year."

LaRoche went on the 15-day disabled list on May 23 with a .172 batting average, planning to spend two weeks doing nothing but strengthening his shoulder through physical therapy. When he resumed throwing for four days, then swinging a bat, the shoulder felt the same.

The problem appeared in Spring Training as a small tear, and LaRoche opted to play through it. But the problem progressed, and an MRI during the season showed "a very large tear."

"Everything we did was to try to safely get Adam out there to produce this season," Douoguih said. "As soon as we realized this was something more problematic, we did a standard program. Everything we did was gradual and really textbook. Unfortunately, he just wasn't able to get through that."

LaRoche's recovery process could take anywhere from three to four months if it is a small, cleanup procedure. If the labrum needs to be repaired, he could miss six to seventh months.

Michael Morse, who has a .303 average with 10 home runs, will remain in the lineup at first base, where he has hit .347 with eight home runs, 17 runs scored and 27 RBIs in 26 games. The former shortstop also played well defensively, although Rizzo said the Nationals will miss LaRoche, who signed a two-year, $16 million contract in January.

"It's disappointing because it negatively affects the ball club," Rizzo said. "It takes a Gold Glove-caliber first baseman, 25 home runs and 100 RBIs out of your lineup, which would affect any team. Nobody is feeling sorry for the Washington Nationals. We have to move on and we had secondary plans in place to fill that void -- and it will be a void."

Desmond, Bernadina return to lineup

WASHINGTON -- Shortstop Ian Desmond returned to the Nationals' lineup Tuesday against the Cardinals, and outfielder Roger Bernadina entered in the second inning as a substitution.

Neither has an injury that appears to be serious. Desmond has played through a left quadriceps injury for weeks and will likely continue to have to do so. Bernadina was originally on the bench on Tuesday as a precautionary measure because of hamstring tightness. He entered the game in the second inning as a pinch-hitter for center fielder Rick Ankiel, who exited with a strained left intercostal (rib cage) muscle.

Bernadina went 2-for-3 with an RBI, and Desmond had a hit in four at-bats.

Manager Jim Riggleman originally opted to sit Bernadina, who improved his average against left-handed pitchers to .188, with Cardinals lefty Jaime Garcia on the mound. It also gave Jerry Hairston Jr. a chance to remain in the lineup in left field. Hairston was hitless in three at-bats.

Hairston played mostly third base while Ryan Zimmerman was on the disabled list.

Stammen's exit leaves Nats with six-man 'pen

WASHINGTON -- The Nationals optioned right-handed reliever Craig Stammen to Triple-A Syracuse on Tuesday, creating room for Ryan Zimmerman and leaving manager Jim Riggleman with a six-man bullpen.

But Riggleman is not concerned with a lack of arms at his disposal. Rather, he is happy the Nationals are in a position to make this move.

"We just had this road trip where we had three relievers who never even got up in the bullpen and had to play catch. This is the most well rested we've been," he said. "You take that, plus an off-day yesterday, and you have three or four guys who haven't gotten any work. That's a good thing -- that means your starters are going deep in games."

The Nationals began the day with the seventh-best team ERA in the National League, a 3.59 mark, and sending Stammen to Syracuse rather than outfielders Roger Bernadina or Brian Bixler provides more options for pinch-hitting or running and defensive substitutions.

But the short bullpen may not be the long-term solution, and if Riggleman is forced to use multiple arms to get through a game, Stammen or another reliever could return.

"If we run into a situation here where we go to the bullpen a little heavy, we can get one here tomorrow," Riggleman said. "We're just a phone call away from having another pitcher here."

Gorzelanny makes first rehab start

WASHINGTON -- A day after making a rehab start with Triple-A Syracuse, left-hander Tom Gorzelanny was back in the Nationals' clubhouse and felt fine.

Gorzelanny felt elbow soreness before landing on the 15-day disabled list and allowed four runs in four innings on Monday in his first rehab outing.

"It went well and I felt strong out there," Gorzelanny said. "I definitely needed it to get my legs back under me. All in all, I felt really good out there."

Manager Jim Riggleman said he would talk with general manager Mike Rizzo, pitching coach Steve McCatty, team physician Lee Kuntz and members of the Syracuse staff before determining whether Gorzelanny will make another rehab start or return to the Washington rotation.

"He may jump in this next one, he may make another rehab start," Riggleman said. "Tom's going to be a big part of this rotation, whether it's five days from now or the next one."