That Sheffield sat out Tuesday night's contest may turn out to be beneficial for him, as he has been battling a balky right knee since the All-Star break. Sheffield "just relaxed" at the team hotel, taking his first full day off from a game since June 12.
"[Manager Joe Torre] has been trying to get me a day off for a while now, but we're trying to fight to get back in it, so I don't want to be sitting down," Sheffield said. "I've tried to stay in there as much as possible, despite how I feel. I just play through it. It might have been a blessing to sit out a game, but now it's out of the way and I can go forward."
The knee injury, which Sheffield said is related to a knot around his patella tendon, is on his back leg, making it difficult for him to push off at the plate. He said he made a slight adjustment to his stance, though he's trying to keep his mechanics in order.
"I've been trying to not let it get out of whack, but it's hard to push off the leg the way I want," he said. "That's where my strength is; I'm not as strong as most guys up top, my strength comes from my legs.
"My legs keep me in balance. People think my mechanics look crazy, but my legs are my foundation. They keep me in place."
Sheffield has no plans to have any tests on his knee until after the season, but he's not worried about the injury having any major impact on him over the season's final month.
"I can get through it," Sheffield said. "Trust me, I'll get through it."
Back at third: Alex Rodriguez, who served as the Yankees' DH on Tuesday night, was back at his familiar spot at third base for Wednesday's game.
A-Rod, who joined Joe DiMaggio as the only right-handed-hitting Yankees ever to hit 40 homers in a season, has been battling a tight right groin for the past two days, but he decided to give it a try in the field on Wednesday.
"I feel about the same. We'll roll the dice and see what happens," A-Rod said. "Hopefully I can get a ball early in the game, get that behind me and go from there."
"I left it to him," said Torre. "He understands the importance of his health."
Rodriguez started all 130 games at third base before Tuesday, when he went 1-for-2 with three walks and his historic home run.
"It's good that I'm not DHing, because I don't know what to do with myself," he said. "I drive myself crazy -- and everybody in here crazy. I have too much energy to DH."
September soldiers: The Yankees will call up three players on Thursday, as rosters can expand up to 40 players.
Left-hander Wayne Franklin, catcher Wil Nieves and right-hander Ramiro Mendoza will join the Yankees for Thursday's game, while outfielder/DH Ruben Sierra will be activated from the DL after missing 41 games with a strained left hamstring.
Mendoza, who pitched for the Yankees from 1996-2002, pitched in 10 Minor League games while completing a comeback from shoulder surgery, and the Yankees feel he can help them out of the bullpen down the stretch.
"I'm curious myself; we certainly know he's pitched under fire and he's responded very well," Torre said. "It's been a slow process for him to get back to being healthy. I trusted him a great deal, and that's something to be said for a ballclub that has been in the race all the time."
New York will bring up additional players when the team returns home next week, including right-hander Scott Proctor, infielder Felix Escalona and outfielder Mike Vento.
On deck: The Yankees and Mariners close out the four-game series with a Thursday matinee, as Jaret Wright takes the mound against Joel Pineiro.