It was a key tune-up for Wednesday's start at Rogers Centre against the Blue Jays, and at one point of the bullpen session, Matsuzaka literally became a mad scientist.
"I think he went through a period where he actually stepped off the mound and got a little frustrated with himself," said Red Sox manager Terry Francona.
Perhaps the anger was therapeutic.
"And then the last 30 pitches, I think he felt pretty good," Francona said. "He commanded. I think the feeling was, 'OK, now just carry that to the game.'"
After producing a 2.70 ERA over his first three starts, Matsuzaka has had a tough time of in his last three outings, giving up 17 runs over 16 innings. The breaking point each time has been one bad inning. In fact, 15 of the 23 runs Matsuzaka has allowed this season have come in six innings.
One key to a turnaround for Matsuzaka is obviously to pitch better out of the stretch.
"Gather your weight, distribute it, get a balance point and then explode to the plate," said Francona.
Pitching coach John Farrell also noted that perhaps Matsuzaka at times has been too pre-occupied with a particular base runner.
"As he's pressed and tried harder for consistency and success, ultimately he's rushed to home plate, he's not maintained his balance point," said Farrell. "As a result, the definition and depth of his pitches is reduced and the overall command suffers."
Matsuzaka never looked more out of sorts than in the first inning of his last start against the Mariners, when he opened the game with three straight walks and put his team in a 5-0 hole before they took a swing. Hence, the extra work at the Metrodome.
"We had set up going into that bullpen [session] really just to establish some relaxation, really just to establish some rhythm, because I really felt against Seattle he was forcing things quite a bit, particularly in the first inning," said Farrell. "It was almost like, physically, he was too strong. He tried overthrow at times. He just really never established a rhythm or a consistent release point. That was definitely one of the goals, to come away from the bullpen in a good frame of mind."
But only a rebound on Wednesday will truly improve Matsuzaka's mood.
Differing opinions on Bonds: Curt Schilling and David Ortiz both expressed their opinions on Barry Bonds and his pursuit of the all-time home record, and they could not have been more different.
Schilling was asked during his weekly radio spot on WEEI-850 AM if fans should hold their noses at the prospect of Bonds passing Aaron.
"Oh yeah. I would think so," Schilling said. "I mean, he admitted that he used steroids. I mean, there's no gray area. He admitted to cheating on his wife, cheating on his taxes, and cheating on the game, so I think the reaction around the league, the game, being what it is, in the case of what people think. Hank Aaron not being there. The commissioner [Bud Selig] trying to figure out where to be. It's sad."
But Big Papi's view is that Bonds actually never did admit to knowingly using steroids and that the Giants slugger should be recognized for all of his hitting accomplishments.
"Have they proved he used steroids?" Ortiz said to the Boston Herald. "But it was a cream or something he was using. He wasn't injecting anything, right? I don't know what steroids can do to you as a baseball player. You've still got to swing the bat, man. If I ever use steroids, and then I know what the difference can be and I'm using them, I'll tell you, 'Yeah, whatever,' but I don't know what the feelings are when you use the steroids. But I can tell you how it feels to pull yourself together to swing the bat. He deserves respect."
The Giants play in Boston from June 15-17, at which point Bonds could be within reach of No. 755.
Lugo due: Francona didn't express any concern about the slow start Julio Lugo is off to at the plate. Boston's new leadoff man entered Tuesday with one hit in his last 15 at-bats. He had a .221 batting average.
"He's got a long history of playing every day and doing well," Francona said. "Everybody goes through it. He's going through it now. There's probably going to be somebody every week that [is struggling]. It's just the way the game is. You can't get nine guys hot at once. It just doesn't really work like that. Guys go up and down. he's in the down right now."
Often times, free agent signees will try too hard to impress their new teammates. Could that be the case with Lugo?
"I don't think so," said Francona. "I think it's human nature to want to get hits. I understand. But by his demeanor, I don't think so."
Lester back at it: Left-hander Jon Lester, whose rehab has been temporarily derailed after some cramping in his left forearm, played catch before Tuesday's game in Toronto. He'll graduate to long toss later this week. There's no word yet on when he will resume his stint at Triple-A Pawtucket.
On deck: In an all-Japanese pitching matchup, Matsuzaka (3-2, 5.45 ERA) will be opposed by right-hander Tomo Ohka (2-3, 5.50 ERA) in Wednesday night's contest. First pitch is slated for 7:07 p.m. ET.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.