Cleveland Indians designated hitter Travis Hafner had surgery on his injured right knee Thursday and will miss four to six weeks, reports ESPN's Buster Olney in a tweet.
Hafner went on the 15-day disabled list on Wednesday with inflammation in the knee. He's hitting a career-worst .242 in 39 games.
The 34-year-old Hafner is in the last season of a six-year, $66-million deal. The Indians have seven players on the disabled list.