The Yankees announced after Thursday's 4-2 win over Texas that they had gotten the 35-year-old Capuano for cash.
Capuano started the season with Boston and went 1-1 with a 4.55 ERA in 28 relief appearances. The Red Sox released him on July 1 and he signed with Colorado. He made four total starts in Triple-A and Double-A for the Rockies.
Capuano has pitched with Arizona, Milwaukee, the Mets, the Dodgers and Boston in parts of 10 major league seasons. He was an NL All-Star in 2006.
Earlier this month, the Yankees made trades to get pitcher Brandon McCarthy from Arizona and third baseman Chase Headley from San Diego.