It wasn't a full-fledged side session, only because the catcher was in a normal crouch for just the last 10 pitches. But it was close enough that Matsuzaka's throwing program is now ready to pick up steam, and the right-hander is confident the upper back tightness that delayed him at the start of camp is now completely in the past.
Will he be ready to start the season on time?
"I think we'll just have to see how it goes," Matsuzaka said through an interpreter. "If I can stay on track, then maybe. But it's tough to say. I think whatever has happened is really, ultimately, my responsibility. And that might be the case -- that I won't be ready quite for Opening Day. But my goal will always be to get ready as quickly as possible."
In truth, the Red Sox are not worried about whether he can be on the 25-man roster that needs to be submitted by Opening Day on April 4. The club has three off-days before it plays its eighth game on April 14.
In fact, barring rainouts, the Sox could get by with just a four-man rotation until April 18. In other words, they will feel no urge to rush Dice-K along.
After what was basically a lost season in 2009 -- Matsuzaka was never 100 percent and played catch-up the entire year -- there is much optimism that surrounds him now.
The righty is in better physical condition than at any point in his career with the Red Sox, and he feels it will translate into the way he pitches.
Pitching coach John Farrell said that Matsuzaka looks far more like the pitcher he was in 2007-08 right now than he did last year. Matsuzaka, who went 33-15 in his first two Major League seasons, took it even a step further.
"As far as I'm concerned and as far as I can feel, I might even be in a better spot than I was back then," Matsuzaka said.
He will throw his first true bullpen session of camp on Sunday and will face hitters at some point next week. The Red Sox don't have a specific date in mind just yet for his first Grapefruit League start, but it shouldn't be that far off.
The Red Sox and Matsuzaka both want to be methodical with his preparation and not take any shortcuts. If that means missing one start at the beginning of the season, so be it. At the same time, nothing has been ruled out.
"I don't know if I can fully and accurately answer the question yet, because I know in his mind, his next goal is to get into a full-fledged bullpen session, like he's been accustomed to, and the game settings will take place at an appropriate time," said Farrell. "Ideally, we'll get each of our starters to 25 innings, roughly. Again, until he's scheduled for a game, we can't begin to calculate how many innings he's going to get in Spring Training, or what we ultimately feel like he's accomplished to be ready to start the season. I'm not trying to dance around your question, but at the same time, I think it's just too early to say, whether it's the first of April or sometime inside the month."
What did Farrell think of Matsuzaka's side session on Friday?
"[It was] consistent with his previous throwing sessions," Farrell said. "He's had no issues getting loose. He maintained his arm slot. Today, there was a little more intensity or aggressiveness to the throws that he made -- the last 10 being a full crouch. And what we've done with the progression is the catcher standing up for the majority of the pitches, and then finishing up from a squat, just to control the angle from the mound and the amount of extension he gets through the throwing motion. But it was a very good session for him today."
Matsuzaka shared Farrell's enthusiasm.
"Not just today, but the whole time since I got back to throwing, I've felt great," Matsuzaka said.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.