The groin wasn't a big issue. But Tazawa was just about at the innings limit the Red Sox had set for him this season, and the club needed to free up a roster spot for middle infielder Chris Woodward.
Tazawa had never pitched professional baseball when the Red Sox signed him to a Major League contract out of the industrial leagues in Japan last December. The plan was that he would spent most of the season in the Minor Leagues and perhaps get a September callup.
As it turns out, Tazawa was summoned in the heat of a pennant race on Aug. 7. That very night, he was called on out of the bullpen and gave up a walk-off home run to Alex Rodriguez, capping a 2-0 extra-innings loss.
But instead of being deflated by such a tough beginning, Tazawa gave the Red Sox important wins against the Tigers and Yankees during his brief rotation stint.
"I had no idea what to expect this year, so I was anxious about a lot of different things, but looking back on it, I had a better year than I could ever hope for and looking back, I think it was a great year," said Tazawa.
The Red Sox couldn't agree more.
"The one thing we really told him today is he's to be congratulated," said Red Sox manager Terry Francona. "He had an unbelievable year. Last year at this time, he was probably just finishing up the industrial league."
Tazawa impressed as far back as Spring Training, when he made five appearances for the Red Sox, giving up just one run over nine innings. The 23-year-old went 9-5 with a 2.57 ERA in 18 starts for Double-A Portland, and 0-2 with a 2.38 ERA at Triple-A Pawtucket.
For the Red Sox, his results were mixed, as he went 2-3 with a 7.46 ERA in six games, four of which were starts.
"He kind of, I don't know if bucks the system is the right word, but he goes through what he goes through," Francona said. "He comes to Spring Training and there's a lot of, I don't know about the hype, but there probably was some. A lot of unknowns with him and he just lit it up in Spring Training.
"He goes to Double-A, and he said the biggest thing of all to deal with was the weather in Portland. But he pitched really well there, made some adjustments. Goes to Triple-A and was probably supposed to stay there and pitch. Because of what happened, he gets called up with us. Really, you know what, did a pretty good job. I think what you'll see next year is you'll see a guy coming to camp that feels he belongs."
Tazawa is eager to see what 2010 might bring.
"Looking toward next season, we've already talked about my training program for the offseason, and I know the workload I'll be facing, but I'm going to work hard and get through it and hopefully, I'll have another good year," Tazawa said. "But as for making the team straight out of Spring Training, I was just given this news today, so I haven't gotten to thinking about that yet."
What did he learn this year?
"One thing that I learned most was really going after strikes and trying to get ahead in the count," Tazawa said. "I think in Japan, there's more of a tendency to use pitches away from the strike zone as well, which wasn't there, so that was one learning experience for me."
And yes, Tazawa is starting to pick up the English language.
"I think I'm starting to understand some of the conversations that take place in the clubhouse, so I think that's a good thing," Tazawa said.
What stands out about his memorable first year in the United States?
"On the field, having the opportunity to pitch in a big league game and also to get a win in a big league game, both were very special moments for me," Tazawa said. "Off the field, I don't think there was any one thing, but I am very grateful for the support system that the Red Sox put in place for Japanese players, because that really allowed me to have less stress than I probably needed to have."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.