THURSDAY, 12:24pm: Matsuzaka will have the operation, according to Jon Heyman of SI.com (on Twitter). Dr. Yocum will operate, probably next week.
WEDNESDAY, 11:18pm: At this point, there is no final decision regarding treatment for Matsuzaka, who will meet with Red Sox officials tomorrow, according to Alex Speier of WEEI.com.
9:50pm: Daisuke Matsuzaka has elected to have Tommy John surgery and will likely inform the Red Sox of his decision Friday morning, according to Gordon Edes of ESPNBoston.com. Earlier tonight, Yahoo's Tim Brown reported that Dr. Lewis Yocum found a significant tear in the right-hander's elbow and that Matsuzaka was leaning toward ligament replacement surgery (Twitter link). Nikkan Sports first reported that Matsuzaka would undergo Tommy John surgery.
The 30-year-old struggled through eight appearances this year before going on the disabled list. He has a 5.30 ERA with 6.3 K/9 and 5.5 BB/9 through 37 1/3 innings in 2011. On May 18th, the Red Sox announced that Matsuzaka had experienced elbow tightness in his previous start and could have a sprained ulnar collateral ligament, and strain to his common flexor mass.
It cost the Red Sox $103MM to acquire Matsuzaka before the 2007 season. He's under contract for 2011 and 2012 and will earn a $10MM salary each year before hitting free agency. Recovery from Tommy John surgery typically takes a year or more, which could mean Matsuzaka returns with three or four months remaining on his original six-year contract.