Philadelphia Phillies left-hander Cliff Lee left Thursday night's game against the Washington Nationals in the third inning of his third start since returning from the disabled list with the same left flexor pronator strain that sidelined him for two months.

Lee retired the first seven Nationals hitters he faced before giving up a double with one out in the third inning. With two outs, Lee threw a pitch to Nationals center fielder Denard Span, tapped his left arm with his glove while looking into the Philadelphia dugout and walked off the mound.

Lee's replacement, Antonio Bastardo, retired Span to end the inning .

The Phillies did not immediately indicate the severity of Lee's injury or how long he might be out.

Since Lee (4-5) returned from his extended stay on the disabled list, he had given up nine runs and 21 hits in 10 2/3 innings.

The 35-year-old veteran has nearly $46 million remaining on his contract through 2015 -- $25 million for next season and a $12.5 million buyout with a $27.5 million club option for 2016.