It turns out there were more to the injuries of Daisuke Matsuzaka during the 2009 season, the Red Sox just weren't aware. Matsuzaka told the Japanese magazine Friday that he injured his leg while training for the WBC and kept the injury hidden from the team, The Boston Globe reports.

The leg injury Matsuzaka talks about altered his mechanics and led to the shoulder injury that put him on the disabled list.

"Early on in January 2009, I hurt my right inner thigh," Matsuzaka said on Friday according to a translator. "I consider movement around my hip joint a crucial part of my pitching motion. It happened during my exercise to strengthen my hip joint that I incorporated into training since 2008. I may have pushed myself just a little too hard. It wasn't the pain that killed me, but it was the regrets and guilt that filled my mind. It was the time to start building up for the season, but I hurt myself because of my own doing."

But even with his mechanics being off, Matsuzaka didn't allow the trainers or medical staff realize the extent of his injury.

"I didn't let them. I didn't want to be the center of concern for people. I didn't tell the trainers. Fortunately, I was in charge of my own training, so if it started to hurt, I could adjust to not hurt myself. But pitching while hiding the injury was very difficult. Even when I didn't feel the pain, my body was holding back because it sensed the danger. So, my pitching motion was more of standing straight up and throwing with my upper body, relying on my shoulder strength more than usual."

Matsuzaka also discussed his meetings with the Red Sox during the season, in which the pitcher voiced his displeasure about the Red Sox' conditioning program.

"(That) was a very important event for me. I think I got through to (the team) that shoulder strength and pitching stamina are two different things. They have generously agreed that I can have long bullpen sessions as long as I can pass the measurement for shoulder strength. The reason I was able to come back strong after my second DL stint was because my thigh was healed and I was able train with the long bullpen session. It was not because I lost weight. If by losing weight you become a better pitcher, I'd lose much more. It is not that simple. I have re-started the exercise to strengthen my hip joint again."