Clemens, who leads the majors with a 1.89 ERA, will miss his start Saturday because of a sore left hamstring, forcing the Astros to give the ball to rookie Ezequiel Astacio.
Clemens tweaked the hamstring in his Sept. 3 start against St. Louis, and has gone 1-2 with a 5.40 ERA in four starts this month while trying to pitch through the injury. He is listed as day-to-day, but Astros manager Phil Garner said he doesn’t expect him to miss any other starts.
“He needs to take the start (off),” Garner said after the Astros’ 5-4 loss to the Cubs on Friday. “It is what it is.”
The 43-year-old right-hander didn’t have an ERA higher than 1.97 in any of the previous five months of this season.
Astacio is 2-6 with a 5.76 ERA in 21 appearances, including 13 starts, this year. He has not started since helping the Astros to a 6-5 win over NL Central champion St. Louis on Sept. 2, when he allowed three runs and eight hits over 5 1-3 innings.
“We just need a good performance,” Garner said. “Nine shutout innings would be nice.”
Philadelphia rallied for an 11-10 victory over Cincinnati on Friday, cutting the Astros’ two-game lead in half.
“We weren’t going to win the rest of them,” said Houston’s Lance Berkman, who went 2-for-5 with an RBI on Friday.
“Nobody expected us to go 9-0 over the last nine games. It would have been nice, but these guys are getting paid to play, just like we are. They’re a tough team. We certainly have our hands full. We just have to regroup and come back.”
Carlos Zambrano will take the hill for Chicago. The right-hander is 8-1 with a 2.36 ERA in 13 starts since the All-Star break.
Zambrano faced Houston on Aug. 17, giving up one earned run on three hits over 8 1-3 innings of a 4-2 victory. He struck out 10.