The right-handed Japanese sensation played catch on a partly cloudy day in front of no fewer than two dozen still photographers and team staff and officials.
Matsuzaka arrived in town after flying into Tampa on Monday night, shadowed by more than 100 Japanese media following his every move.
The 26-year-old joined fellow pitchers Jonathan Papelbon, Jon Lester and others who also arrived early in camp.
Pitchers and catchers aren't due to report until Friday, with the first workout planned for Sunday.
Photographers, most from Japanese organizations, kept busy for the 20 minutes they were allowed to watch the Japanese pitching star who signed a $52 million contract with Boston in December. Some waited four hours outside the facility before Matsuzaka arrived behind the wheel of a black Cadillac Escalade just after noon ET.
A half hour later, wearing a red Red Sox T-shirt, he walked out of the clubhouse for a brief tour of the grounds before starting his short workout.
At 12:35 p.m., he began stretching. At 12:40, he started jogging. At 12:46, he put on his glove. At 12:47, he made his first throw to catcher George Kottaras, a top prospect obtained last September from San Diego for pitcher David Wells.
Kottaras had been working out in the clubhouse when he volunteered for the assignment. That gave the catcher who has yet to play in the majors plenty of attention.
"It's my first time experiencing this for a long-toss session," Kottaras told the AP. "I don't think I'm the story."
Mike Petraglia is a contributor to MLB.com. Material from The Associated Press was used in this report. This story was not subject to the approval of Major League Baseball or its clubs.