Cleveland's closer didn't pitch this season until May 8 because of a strained muscle in his upper back that landed him on the DL during spring training. Now, he has a blistered right index finger.
"Kerry was dealing with this for a while and it just didn't get better during the All-Star break," manager Manny Acta said.
Wood has had an uneven second season with Cleveland, which signed him to a two-year, $20-million contract in December 2008.
In 23 outings, the 33-year-old righthander is 1-4 with a 6.30 ERA and eight saves.