Daisuke Matsuzaka started an exhibition game against Seibu at MetLife Dome earlier today. He developed tightness in his right thigh (adductor muscle) while pitching in the fourth inning. He left the game with the bases loaded and two out. He was hoping to throw about 100 pitches, but left after throwing seventy-one. He later told reporters he first started feeling discomfort in his right leg in the first inning.
[UPDATE 3/19 @ 10:49pm]
Matsuzaka participated in pre-game practices at Yokohama Stadium today. He did some running and played some catch. He appeared to be okay.
Source: Sponichi 3/19/2017
[UPDATE 3/19 @ 11:48pm]
Matsuzaka is currently slated to remain with the Ichi-gun team.
Source: Tokyo Sports 3/19/2017
[UPDATE 3/22 @ 12:12am]
Matsuzaka could toss a bullpen session on March 22. His workouts on March 21 included playing catch for about third minutes and running dashes in the outfield.
Source: Nikkan Sports 3/21/2017
[UPDATE 3/22 @ 5:44pm]
Matsuzaka threw seventy-five pitches in the bullpen today. He is currently slated to start a game against Hiroshima on March 25. This will most likely be his last chance to win a spot in the opening day starting rotation.
Source: Tokyo Sports 3/22/2017