Strasburg exits early with left-side tightness

WASHINGTON -- Nationals right-hander Stephen Strasburg left Saturday's 9-3 win over the Giants in the fourth inning because of tightness in his left side and was replaced by right-hander Tanner Roark.

Strasburg was cruising for 3 2/3 innings, allowing one hit and striking out three batters, as the Nationals led the Giants, 3-0. Nationals catcher Wilson Ramos believed that Strasburg was having his best game of the season.

"I was excited about the last three innings, because he was throwing really [well]," Ramos said. "I was telling Desi [shortstop Ian Desmond], and Desi told me he was impressive today."

After getting Buster Posey to ground out to second baseman Danny Espinosa for the second out in the fourth inning, manager Matt Williams, pitching coach Steve McCatty and assistant athletic trainer Steve Gober went to the mound to see if something was wrong with Strasburg, who grabbed at his left side.

Strasburg tried to talk Williams into letting him stay in the game for another inning. A few minutes later, however, Strasburg was removed from the game. As of now, there isn't talk of putting Strasburg on the disabled list.

"We will continue to evaluate [his left side] and see how he is tomorrow," Williams said. "Given his season, so far, I don't want to take a chance there."

It marked the third time Strasburg had to leave a game this season because of an injury. He previously had problems with his back and neck, respectively. Those injuries were caused by poor mechanics. The neck problem landed him on the disabled list for almost a month. It's not known if mechanics were the cause of the side injury.

After the game, Strasburg acknowledged to the local media that his left side was feeling tight.

"Since that was going to be the case, I iced it a couple of times," Strasburg said. "I really don't have an explanation [for the injury]. Everything felt good. I threw a pitch to Posey. He grounded out and I felt the grab [in my side]."

Strasburg has pitched well since coming off the disabled list, allowing two runs over 15 2/3 innings.