Though Wood began the 1964 season with Boston, he was given his outright release to Seattle in the midst of May after posting a 17.47 ERA in four games. Pitching coach Bob Turley thought he was not suited to success at Fenway Park. Spending the next few months in Seattle, Wood posted a 15–8 record, ranking among the league leaders in wins (tied for third with three other pitchers behind Bob Locker's and Ken Rowe's 16), ERA (2.30, second to Bruce Howard's 2.20), strikeouts (197, second to Al Stanek's 220), and innings pitched (211, seventh). He was also selected to the league's All-Star team. The Red Sox chose not to promote him in September, but Wood had his contract purchased by the Pittsburgh Pirates on September 6.