This Yankees outfield does not have much star power, especially when compared to past great Yankee teams. However, it is still a solid starting trio there. There is not much in the way of backups, and the farm system is not close to producing help.
Left Field: Brett Gardner homegrown starter
Gardner is the one true speed burner that the Yankees have on their roster. He was a legitimate stolen base threat in his first full season as the starter in LF (47 steals, 9 caught). The tradeoff is that Gardner has almost no power. However, he drew a lot of walks (13.88% of PAs) in 2010, but he struck out a decent amount as well (17.75%). This makes him an almost ideal leadoff hitter. However, New York sees his lack of power and puts him down in the 8th or 9th hole as a second leadoff hitter. Gardner is 27 years old in 2011, so another solid season from him is certainly possible. Former Yankee Johnny Damon is someone that New York is seriously considering for their 4th outfielder spot. Damon has little power, but he still controls the strike zone fairly well. Defensively, his range is pretty good though his arm is a major liability.
Center Field: Curtis Granderson patrols here
Curtis Granderson had a slightly above average offensive year with the Yankees last season (.247/.324/.468 over 528 PAs). He did provide power (24 homers) to a team that was loaded with it in 2010. His defense in center field is a shade above average which helps out the Yankee outfield defense. Granderson's biggest problem was an inability to hit lefties (.234/.292/.354 over 174 PAs) in 2010. This is something that is a consistent weakness throughout his career, and makes him a candidate for platoon in center field if the Yankees can find a reserve outfielder that can play center.
Right Field: Swisher is the starter
Nick Swisher had a very nice 2010 season (.288/.359/.511 over 635 PAs) for the Yankees. He is a hitter that really makes the pitcher throw a lot of pitches (even for a Yankee). Defensively, he is solid enough, but is nothing special. Swisher had an excellent walk rate in 2010 (9.13%), which helped against his healthy (21.89% of his PAs) strikeout rate. Swisher was a major power source for the Yankees in 2010 (65 extra base hits was good for 3rd on New York). He is a solid starter for the Yankees in 2011.
Marcus Thames provided an above average offensive season for the Yankees in 2010 (.288/.350/.491 over 237 PAs) as the nominal starting DH/4th outfielder role. Thames is below average corner outfielder defensively, and he is unable to play center. That makes it very unlikely that he will be back with the Yankees since Posada is moving over to a full time DH role. Thames is going to be 34 years old in 2011, and he still has excellent power. There is a chance he will latch onto a bench spot with a team that needs a guy that can mash lefties.
The Yankees do have some serious interest in free agent Andruw Jones to be their fourth outfielder. He had an above average offensive year in 2010 (.230/.341/.486 over 328 PAs) with the White Sox. Jones is capable of playing all three outfield spots, though at center field his range is a touch short. In addition, Jones mashed lefties in 2010 (.256/.373/.558 over 102 PAs). That would allow the Yankees to limit Granderson's exposure to left handed pitching. Jones is not a perfect solution, but he would be a good fit for the Yankees needs.