NEW YORK -- Nick Swisher returned to the Yankees' starting lineup slotted as the designated hitter on Sunday night, but he could be starting in the field as soon as Monday.

"If they needed me to be out there, I'd do everything in my power to go out there and play," said Swisher, who has been recovering from a mild hip flexor strain since July 20. "I just feel today, maybe just going as a DH getting used to that game speed-type atmosphere, and then move back out to the outfield tomorrow or the next day."

A gap emerged this week between Swisher and manager Joe Girardi's evaluation of the right fielder's recovery. The Yankees insisted they weren't being overly cautious with Swisher, and Girardi said Swisher wasn't ready to return to action just yet. Swisher -- who struck out in his lone pinch-hit at-bat on Saturday -- has said he's felt fine to play since Friday.

"Ninety-nine percent of players are all the same," Girardi said. "They all want to go out there and play, whether they're battered and beaten up and shouldn't be out there, because it's what they love to do. I was the same way. Sometimes you try to hide things and mask things, but as a manager, you have to listen carefully. You have to listen to your medical people. You have to listen, maybe to clues that he drops other places that he doesn't realize a player might drop, and then make a decision."

After Saturday's game, Swisher opposed Girardi's concern that he wasn't running the bases at 100 percent during batting practice, but on Sunday he admitted he was probably only running at 85 to 90 percent during the drill. Girardi has held him out of the lineup for that reason, wishing to avoid any setbacks that could require more time to heal.

"I think anytime when you're dealing with strains and something like that, you're kind of on that fence whether it could be a week, eight days," Swisher said. "I appreciate the fact that these guys are looking out for me."

Swisher worked with the Baltimore Ravens' Ray Lewis, the New York Jets' Antonio Cromartie and the Green Bay Packers' Clay Matthews at Proactive Sports Performance in Westlake, Calif., this winter, in an attempt to lose weight and become leaner. He has encountered some trouble as a result, injuring his groin during Spring Training and now having to miss time during the season.

"It's kind of led to a lot of bumps and bruises," Swisher said. "I feel like I just need to do a lot more stretching, maybe a lot more massages to try and lengthen those muscles out a little more so I don't have to deal with this anymore."

Girardi said Swisher is still day to day, but he liked the way his right fielder ran the bases on Sunday. If all goes well Sunday and Swisher feels healthy on Monday, Girardi might not hesitate to pencil him in for the outfield in the series opener against Baltimore.

"In the long run, skip's right," Swisher said. "Sometimes it takes another side or another party to really kind of tell you things that could happen, because this is a special year, and I don't want to miss any part of this."

Phelps has impressed since returning to Yanks

NEW YORK -- David Phelps did something on Saturday that he hadn't in six previous appearances since rejoining the Yankees from the Minor Leagues: allow a base hit.

Phelps permitted a single to Red Sox third baseman Will Middlebrooks in his scoreless two innings of work during New York's 8-6 loss to Boston, but that has been the only blemish the 25-year-old has incurred in 7 1/3 scoreless innings since his July 18 recall.

"I think that consistent work has helped him as much as anything; the innings he was able to go down and get built back up and got his arm strength going again," Yankees manager Joe Girardi said.

Phelps is in his third stint with the Yankees this year and has made 16 relief appearances, striking out three batters in the eighth inning on Saturday. On Wednesday in Seattle, Phelps threw 1 1/3 perfect innings for his second Major League win, and on July 22 in Oakland, he retired all five Athletics he faced, with three strikeouts.

Phelps also made three starts for the Yankees this season and is 2-3 with a 2.59 ERA, owning 54 strikeouts in 48 2/3 innings.

"We sent him down to get work to get built back up, and he's had consistent work about every third day," Girardi said. "He's been really good."