Damon, 34, who relies greatly on his speed, said afterward that he might have had healthy wheels for 40 of the 141 games he played last season, when he batted .270, his lowest mark since he broke into the Major Leagues in 1995. His 27 doubles last season were his fewest since he hit 12 in 1997, and his two triples were a career low.
"Probably at the end of last year, I actually felt I got things going into the postseason," said Damon, who already has a dozen doubles in 30 games. "I consider myself a pretty good player in this league, and I don't want people to forget about me."
Damon had the fans on their feet on Saturday, and Mussina had the crowd yelling, "Moose, Moose, Moose," in appreciation on several occasions.
Like Damon, Mussina, 39, battled through health issues early last season and was unable to win at least nine games before the All-Star break after doing so for 13 straight seasons. His 5.15 ERA in 2007 was a career high, and his 11 victories equaled his career low.
"I've been lucky enough to play a long time," Mussina said. "If you play long enough, injuries are going to get you sooner or later. I had a tough year last year, and that's the truth of it.
"I just wanted to come out this year and prove to myself, more than anything, that I could still be competitive at this level and do what I've been doing for all these years. You have a bad year and you don't know what is going to happen the next year. When you start getting up in your 30s, you are not really sure what is going to happen. I wasn't really sure if all that stuff that happened to me last year was going to linger, carry over or cause any residual problems."
Mussina made some adjustments with his location and changeup late last season. He arrived at Spring Training this year healthy, and he has been able to pitch effectively as a result, going 4-3 with three straight wins and a 4.43 ERA.
Yankees manager Joe Girardi, who has been watching Damon and Mussina for years, appreciates what he has seen so far in 2008.
"The Johnny that I know, the one I saw [while] playing against him and the one I saw playing for the Yankees the last couple of years ... when Johnny is going right, he's a pain," Girardi said.
Damon led off the bottom of the first with a double to right-center field off hard-throwing righty Felix Hernandez, who took the mound with a 2-1 record and a 2.22 ERA and left after giving up six earned runs on 12 hits in 5 2/3 innings. Damon scored the first run of the game on a single by Bobby Abreu.
Seattle tied the game in the top of the third inning, but its joy was short-lived. Yuniesky Betancourt hit a two-out single and scored on a single by Ichiro Suzuki. The Yankees turned a double play earlier in the third to help Mussina, who had the benefit of another in the fourth.
Damon got the Yankees off to their second rally with a hard-hit one-out double, the 400th of his career, to left-center field in a three-run third. Derek Jeter followed with the 390th double of his career to score Damon, and six more Yankees stepped to the plate before Hernandez was finally able to sit down.
Jose Molina ended an 0-for-23 slump with a leadoff single in the sixth, and Damon -- who went 3-for-5 against the Mariners in the first game of his career, on Aug. 12, 1995 -- hit a first-pitch homer to right to put the Yankees in control.
Mussina has given up just five earned runs in 18 innings during his personal win streak. The victory was the 254th of his career.
"You don't win over 250 games by accident, but as you grow older, you have to make adjustments, and Moose has done that," Girardi said, adding that he may give the veteran an extra day of rest before he starts again.
"Stuff was nagging at me that made it difficult for me to do what I wanted to do," Mussina said of last season. "But coming into this year feeling 100 percent again, I've been able to do what I want to do -- for the most part, make the pitches I want to make. I know the ball isn't going to come out of my hand at 93 [mph] ever again, so I have to make the most of what I have, and I've been doing OK."
So has Damon, who has 12 hits in his last 28 at-bats.
"It was the first time in my career I had to deal with a few more injuries than I would have liked," Damon said. "My legs are the reason the scouts came out to watch me play. Without having them, last year was a little scary."