Matsuzaka, whose agent is Scott Boras, posted a 3.92 ERA in 103 1/3 innings for Cleveland's Triple-A squad in 2013. He hasn't pitched in the Majors since 2012, where he made 11 starts for the Red Sox. The season prior, he only made 7 starts, before being lost for the season due to Tommy John surgery.
Matsuzaka was pursued by the Mets over the winter, but he ultimately chose to sign with the Indians.
This is a solid move by the Mets for a variety of reasons. The Mets have recently lost Jeremy Hefner and Jenrry Mejia for the remainder of the season, and they need someone who could eat up some innings.
Assuming Matsuzaka stays healthy, he has every opportunity to finish the 2013 season strong, and he heads into free agency. Coming out of Japan in 2007, Boston fans expected him to be the next big thing in the game, but he looked overmatched for the most part.
His best season came in 2008, where he had a 2.90 ERA in 29 starts. The problem was he also had a league-leading 94 walks. Matsuzaka's control has always been an issue, as he owns a career 4.3 BB/9 rate.
I know many Mets fans would like to see some young arms in September, such as Jacob deGrom and Rafael Montero. But the reality is they are on tight innings limits, and rather than risk a potential injury, the team has basically decided to be cautious by signing Matsuzaka, who will likely eat some innings from now until the end of the season.