My recommendations...
After living in NY for 52 years..I finally did the tourist double decker bus, and LOVED it...from Harlem to Battery Park in two days..hop off and seek out new finds..We recommend to others family/friends..one of those things you have to do...we jumped off at Seaport to use the chaise chairs on the top floor of Mall, overlooking the Hudson..free you know..and we sat there with $4 beer from the food court watching the yachts, boats leave for the Sunset cruise..aaahhh the joys of life on a budget.
Would also recommend Circle Line Cruise..3 hours tour around Manhattan Island..
Since your a Yankee Fan..why not plan an earlier visit to Yankee Stadium for:
Monument Park, a museum in and of itself, recognizes former Yankees greats and has been relocated to its original position behind centerfield. On game days, it opens with the gates and remains accessible until 45 minutes prior to the game start time, subject to capacity limitations. It is closed between doubleheaders and during inclement weather. Signage throughout Yankee Stadium will direct guests to Monument Park. Yankee Stadium staff is also available to assist guests. Batting Practice Remember fans, on game days, arrive early. Yankee Stadium Gates on Babe Ruth Plaza and Gates 2 and 8, open three hours prior to the start of every home game. All fans are encouraged to arrive early to enjoy batting practice and infield workouts from select areas of the Field Level and the Bleachers; specifically, all fans may watch batting practice and infield workouts from Field Level Sections 103, 104, 105, 106, 107, 108, 109, 110, 111, 129, 130, 131, 132, 133, 134, 135 and 136 and from all Bleachers Sections. Please note, on certain game days the Yankees may elect not to take batting practice, infield workouts or both. Those fans who take advantage of the opportunity to enjoy batting practice and infield workouts from the Field Level and/or the Bleachers may remain until the players leave the field following the conclusion of the Yankees batting practice or 1 hour and 45 minutes after the Gates open. At that time, all fans will be asked to return their respective seats.