Roger Clemens left Game 1 of the World Series after two innings Saturday night because of a strained left hamstring, an injury that has bothered the Houston Astros' ace since early September. Clemens allowed three runs and four hits over two innings against the Chicago White Sox, and left with the game tied at 3. This was the first time he had started a Series opener. The seven-time Cy Young Award winner threw 54 pitches -- 25 in the first inning and 29 in the second, after which he walked gingerly down the dugout steps and disappeared in the tunnel that leads to the clubhouse. He struck out one with no walks. Wandy Rodriguez, a rookie left-hander who started during the regular season, replaced the 43-year-old Clemens at the start of the third inning. If Clemens is unable to pitch any more, the Astros would not be able to replace him on their World Series roster.