BOSTON — Tim Wakefield will replace struggling Brad Penny in the Boston Red Sox rotation.

Manager Terry Francona said Saturday the 43-year-old Wakefield, who made his first All-Star team this season, will start Wednesday night against the Chicago White Sox. He didn't say when Penny would pitch again.

Wakefield (11-3) last pitched for Boston on July 8 and made his second rehab start Friday night since going on the disabled list July 21 with a strained lower back, left hamstring and left calf. In 5 2-3 innings for Triple-A Pawtucket, the knuckleballer allowed one run and two hits in a 2-1 win over Rochester.

Penny (7-8) also pitched Friday night, allowing eight runs in four innings of a 20-11 loss to the New York Yankees. He is 1-6 in his last 11 starts.