Matsuzaka is a free agent after the season and the Red Sox aren't expected to bring him back.
His six-year tenure started with two solid seasons, only to be followed by four years marked by injuries and under-performance.
Matsuzaka has pitched 116 games for the Red Sox, going 50-36 with a 4.47 ERA. To get him, the Red Sox submitted a posting fee of $51.1 million to the Seibu Lions and then inked the righty to a six-year, $52 million contract.
Dice-K has pitched just 55 times over the last four seasons, going 17-21 with a 5.42 ERA.
"I'm not going to try to evaluate his overall time. I didn't really watch a lot of it," said manager Bobby Valentine. "I know that one year he won a lot of games and he won a seventh game or something. He has a bit of stuff on his resume.
"But this year, I didn't know what to expect coming back from an injury. ... I don't think he fully recovered [from Tommy John surgery]. He says he has and the training room says he has, but I still think there's a little mental hurdle he has to get over that's very similar, and I don't want to just lump Japanese guys into one category, but in Spring Training, [Junichi] Tazawa had a mental hurdle to get over and he wasn't throwing the ball the way he was capable of. And then one day he broke through. And I think the same thing happens with everyone coming back from injury."
After competing against Matsuzaka in Japan, Valentine enjoyed his one year with the righty.
"Well, I didn't get that chance to work with him that much, but [pitching coach] Randy [Niemann] was there a lot with him," Valentine said. "My interaction with him, I felt he was always a willing and able candidate to do whatever he was asked to do. He never rejected an idea. He always wanted to do well. I don't know if you could ask anything more."