All-star knuckleballer Tim Wakefield is headed to the disabled list. The Boston Red Sox say Wakefield, who turns 43 next week, has a strained lower back. Right-hander Clay Buchholz was recalled from triple-A Pawtucket to start in Wakefield’s place Wednesday night in Texas. Manager Terry Francona said Wakefield got hurt throwing on the side Saturday. Wakefield isn’t sure when he’ll try to throw again. Wakefield (11-3) last pitched July 8 against Oakland, when he allowed three runs over six innings for a victory, and is 5-0 his last seven starts. He has a 4.31 ERA this season. Buchholz started Boston’s first game after the all-star break, earning a victory against Toronto in his only major league start this season before being sent back to the minors.