CINCINNATI -- A day after they learned they'll miss outfielder Jayson Werth indefinitely, the Washington Nationals lost starter Stephen Strasburg at least temporarily.

Strasburg left after only 16 pitches because of a stiff neck, and Zack Cozart had three hits as the Cincinnati Reds rallied against Washington's bullpen for a 5-2 victory on Friday night.

The Reds took advantage of Strasburg's quick exit to win for only the second time in 12 games.

Strasburg had no problem with his neck in the first inning, when he gave up a solo homer by Joey Votto, his first since April 28. As he sat in the dugout between innings, the left side of his neck tightened up.

"It's pretty stiff," Strasburg said after the game. "I don't know why. I felt fine in the first inning. Once I sat down before the second, it kind of tightened up a little bit. It was hard for me to turn my head to the left."

He walked Brayan Pena on his 16th pitch to open the second inning and left the game. It's unclear whether he'll have to miss his next scheduled start.

"We don't know at this point," manager Matt Williams said. "We'll see how it is tomorrow and evaluate it."

Strasburg had a rough May, failing to last four innings in four of his five starts. He left one start with tightness behind his shoulder.

"It's just something I've got to pull through and know it's going to get better eventually," Strasburg said.

The NL East leaders played their first game since a CT scan found that Werth broke his wrist in two places when he was hit by a pitch on May 16. He's sidelined indefinitely.

Taylor Jordan (0-1) took over for Strasburg and gave up three runs in the sixth. Brandon Phillips -- limited to pinch hitting because of a sore toe -- tied the game with a sacrifice fly. Billy Hamilton hit a soft liner to centre for a single that made it 3-2. Hamilton then stole second, and came home on Cozart's third single of the game.

"The blooper over second base (by Hamilton) was not a bad pitch," Jordan said. "I just got unlucky out there."

Anthony DeSclafani (3-4) went six innings for his first win since April 20.

J.J. Hoover fanned Ian Desmond to end a bases-loaded threat in the eighth. Aroldis Chapman gave up a single to Bryce Harper in the ninth while getting his eighth save in as many chances.

Todd Frazier added a solo homer, his 15th, as the Reds pulled away. Thirty of his 44 homers in the last two seasons have come at Great American Ball Park.

DeSclafani gave up a pair of runs and eight hits. Desmond singled in the first inning, extending his hitting streak to 13 games.

STREAKY NATIONALS

Desmond's 13-game hitting streak is two shy of his career high. Teammate Wilson Ramos hit safely in 19 straight games from April 24 to May 19, the longest streak in the NL this season.

CHAT AT FIRST

Harper was unhappy when Tony Cingrani hit him in the back with his first pitch in the seventh inning, staring at the pitcher while taking his time going down the line. Votto had an animated chat with Harper when he reached first base.

"What are you going to do?" Cingrani said. "He should've jogged. Be a baseball player. Sorry I hit you. Run."

TRAINER'S ROOM

Nationals: Right-hander Doug Fister, who went on the disabled list on May 15 with tightness in his forearm, threw without problem on Friday. He hasn't yet thrown a bullpen session.

Reds: Johnny Cueto, sidelined by inflammation in his pitching elbow, won't start again until at least next week.

UP NEXT

Nationals: Left-hander Gio Gonzalez is 2-1 with a 1.06 ERA in five career starts against the Reds.

Reds: Raisel Iglesias makes his fourth start overall and his second filling in for Cueto. He lasted only three innings in a 5-2 loss in Cleveland on Sunday.