Hindered by inflammation in his left knee, Matsui had tried unsuccessfully to get back to the Major Leagues after going on the disabled list in late June, showing progress but forced to shut it down when the knee swelled more. This time, Matsui was more cautious -- and it clicked.
"There was some uncertainty whether I was going to be able to come back, so to be able to be here, I'm definitely happy," Matsui said through an interpreter.
The 34-year-old could be a valuable late-season addition to a Yankees lineup that has struggled to put runs on the board in numerous recent games. Matsui was hitting .323 with seven home runs and 34 RBIs in 69 games before being sidelined with the injury, which will almost certainly require surgery after the season.
"He's been a big part of the lineup over the years here," Yankees manager Joe Girardi said. "His at-bats are always good and he's a professional hitter. You don't worry about left-handers or right-handers against him. He makes your lineup deeper and we look forward to him staying healthy for the last month and a half here."
Matsui was put to an immediate test on Tuesday, dropping into the No. 7 spot in the lineup as the Yankees prepared to face Blue Jays right-hander A.J. Burnett. Matsui appeared in three Minor League games for the Class A Tampa Yankees last week and logged 15 simulated at-bats on Sunday leading up to his activation.
"Matsui brings consistency every day," Girardi said. "He usually does very well in the big spots. His at-bats are very good. I know he hasn't played in almost two months, but I'm a believer that it's not going to hurt him. I believe that he's going to come out and be strong for us."
Because Matsui is strictly a designated hitter from this point, the move makes Johnny Damon the Yankees' everyday center fielder. Rookie Brett Gardner will become a reserve outfielder, with Justin Christian having been optioned to Triple-A Scranton/Wilkes-Barre in a corresponding move to Matsui's activation.
Matsui's place as the designated hitter is not ironclad, however, because Matsui will have days off here and there as the Yankees look to protect his left knee. Girardi said that he received good reports on Matsui's ability to run from first base to third base in Tampa, Fla., but said that would not incline him to try Matsui in left field except for the most dire of circumstances.
"It'd have to be quite an emergency," Girardi said.
Matsui said that he will not play wearing a brace on the left knee and admitted that he does not feel 100 percent, but said he believes he is good enough to play -- part of the reason he staved off surgery in favor of an attempt to make it back to face big league pitching again this season.
"I still wanted to contribute and be a strength of this team," Matsui said. "I want to be part of helping this team win a championship. There was part of me that believed I could still make it back. That controlled my decision."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.