Jon Lester did it yesterday, talking about how much he enjoys working with Josh Beckett, Clay Buchholz, and John Lackey. Matsuzaka’s name never came up.

The Red Sox spent $103.1 million in 2006 to land Matsuzaka, a star in Japan. But as his fifth season with the team commences, the 30-year-old righthander is largely an afterthought. Even the large group of reporters representing media outlets in Japan has dwindled to a diehard dozen. New Twins infielder Tsuyoshi Nishioka is a bigger story.

“Every time he takes the ball now, it’s not quite as big an event,’’ said manager Terry Francona.

There are valid reasons for that. Matsuzaka is 46-27 with the Red Sox but has a 4.18 earned run average and has averaged 4.3 walks per nine innings. Of the 64 pitchers in the majors who have thrown at least 500 innings the last four years, he ranks 34th in ERA.

Only three times in the last two years has he won two starts in a row.

“Good and bad. I had a good time and bad experiences as well,’’ Matsuzaka said via new interpreter Kenta Yamada. “I would like to use the four years of experience to have a better performance this year.’’

The Sox hope that will be the case, but aren’t predicting it. Matsuzaka arrived in camp with a dark tan and a few less pounds.

He showed off his fitness yesterday by throwing 45 pitches in the bullpen, 15 more than any of the other starters.

But Francona has learned the folly of trying to guess what will happen next.

“We’ve kind of been all over the spectrum; we’ve touched it all,’’ he said. “We’ve seen him really good; we’ve seen him where he can’t take the ball; we’ve seen where he doesn’t throw strikes.’’

The first step will be staying on the mound. Matsuzaka has thrown only 380 1/3 innings the last three seasons, missing approximately 33 starts because of injury.

He is a regular on the rehab circuit, making 10 starts for minor league affiliates.

The Red Sox have one-time starter Tim Wakefield in their bullpen for those almost inevitable times when Matsuzaka will be on the disabled list.

“I just want to stay on the mound throughout the whole year in the major leagues,’’ Matsuzaka said. “The past two years, I was not 100 percent confident about my physical condition. However, this spring training, I feel very good.’’

Matsuzaka was 9-6 with a 4.69 ERA last season.

After a rocky 2008 season that included bickering with management, he settled into a lesser role in the rotation and was fairly productive as the spotlight shrunk.

Teammates regard him as baseball’s version of an independent contractor. Matsuzaka is on the roster but is not really part of the social fabric of the team. Beckett, Buchholz, Lackey, and Lester move as a group while Matsuzaka works primarily with the staff members assigned to him. The language barrier is part of it. But few inroads have been made in the last four years, leaving Matsuzaka a nodding acquaintance for most of the players.

Asked yesterday what players he was close to or learned something from, Matsuzaka looked to the skies for a few seconds before answering.

“There is no one specific person,’’ he said.

New pitching coach Curt Young, who spent the previous seven seasons with Oakland, is looking forward to working with Matsuzaka.

“When you see him as an opposing pitcher, he’s a guy who can do a lot of things with the baseball,’’ said Young. “A lot of different speeds, a lot of different areas he can locate the baseball. That’s what I saw [yesterday] and that’s good to see.

“He knows his program, so as long as he’s strong and healthy enough to do the things that he wants to do, we’re definitely good with it. He’s been comfortable with what he’s doing and we’re going to get him through this spring training and get him going.’’

General manager Theo Epstein said he does not regret signing Matsuzaka. But the final two years on his contract probably will be the final judge of whether that bold move was a good idea.

“He had two really good seasons to start, then had an injury-plagued [2008],’’ said Epstein. “Last year was a bit of both. Flashes of dominance, a lot of inconsistency.

“He helped us win a World Series. He had two seasons where he was one of the better starting pitchers in the league and the last two years haven’t been what we wanted. The rest is still to be written.’’

Nick Cafardo of the Globe staff contributed to this report. Peter Abraham can be reached at pabraham@globe.com. Follow him on Twitter @peteabe.