Some of the top contenders for the first base job are Shelley Duncan, Wilson Betemit, Morgan Ensberg, and Jason Giambi.
Duncan would be a great fit at first base.
Duncan, in his young MLB career, has proven to be a great hitter since being brought up by the Yankees last season. If the first base job goes to him, he clearly has shown why he would get it. He is a dependable hitter that the Yankees need. Duncan has also shown his athletic ability on the playing field as well.
Ex-Dodger Wilson Betemit, who was brought in last season through a trade that sent Scott Proctor to the Dodgers, has proven to be a good backup infielder.
You can rely on Betemit when A-Rod or whoever was playing first would rest. Betemit can play first, second, and third. He is a very good option as a bench player, his hitting abilities at the plate aren't that bad either. I don't see Betemit starting at first, but I do see him making the team as a bench player.
Another player who has played first base in his day is ex-Astro Morgan Ensberg.
Ensberg, over his career, has shown that he can start at first base and prove to be a good player. He has the abilities to start at first, but just lacks something. Ensberg is reliable at the plate and on the field.
The only place that you could put Giambi at, besides DH, is at first. Giambi has had some struggles at first in the recent past, and has had some success as well. Giambi probably is the best option at first base for the Yankees—not for his athletic ability, but as a hitter in the everyday starting lineup.
Giambi will be the starting first basemen on Opening Day. Overall, he is the better hitter, and he can play first, as he has shown that throughout his career.
I see the starting first base job coming down to Giambi and Duncan. I wouldn't be surprised if either of them got the nod to start. And if one starts over the other, I can see them rotating every now and then.
Whoever the Yankees select as their starting first basemen, they should be successful.