He then learned, he said, of the 8.9-magnitude earthquake that struck northeastern Japan and spawned a tsunami.
"It was definitely shocking waking up and hear the news," Matsuzaka said. "Once I turned on the television and saw what was going on, it was very shocking, very scary to see that."
Matsuzaka said he has been in e-mail contact with his family and numerous friends, all of whom said they were safe, though they reported some damage. "My parents are fine," Matsuzaka said.
Pitcher Hideki Okajima reported that his family was safe, as well.
Mikio Yoshimura, the team's Japanese media liaison, said he also checked with pitcher Junichi Tazawa and new Japanese minor leaguer Itsuki Shoda, a left-handed reliever, and they, too, said their families were safe.
Matsuzaka and Okajima's immediate family members -- wives and children -- are all in the United States.
Matsuzaka's parents live outside Tokyo, about 200 miles south of the area most directly affected. Okajima's parents are in Kyodo, in the southern half of Japan.
Matsuzaka said the relatives he was most concerned about were on his mother's side, including his grandmother, many of whom live in Aomori, north of the earthquake zone. Matsuzaka said he had not yet been able to contact them.
Phone contact was very difficult, he said, though he had more success with e-mail.
"There's no time to alert people," he said of the earthquake, "which is what makes it so difficult and scary."
Okajima is scheduled to pitch out of Boston's bullpen Friday.
Gordon Edes covers the Red Sox for ESPNBoston.com.