The team has many options, which are listed below.
Internal options, among others
The Yankees could go with internal candidates like Melky Mesa or Zoilo Almonte, but neither of them are very experienced so there is a lot of risk there. The team would probably be smart to go with a more experienced option, but Mesa and Almonte could probably do decent jobs as stopgaps.
It will be difficult for the Yankees to take on significant payroll in any move they might make, as the team is still trying to stay under the $189 million threshold.
Despite recent rumors that he will be retiring at the end of his current deal, the Yankees have been linked to the Angels outfielder. This move appears unlikely as the team is looking to cut costs, and Well is not going to help them do that. One also would have to wonder if Wells is even an upgrade over what the team currently has.
The article also says that the Angels are not jumping at the idea of trading Wells, but if they were presented a deal I am sure it would be difficult for them to say no. I don't think it would make sense for the Yankees to go over the threshold and take on another big contract just to fill-in for Granderson for a month or two.
Soriano to return?
Another rumor that has been floated is Alfonso Soriano being returned to his original team. The corner outfielder could provide a bit of relief to the team's loss of power, but would come at an expensive price. Soriano of course began his career with the Yankees, but as he said, it has been a long time since he played for the team.
I think that Soriano could be a nice addition, but the Cubs would need to eat some money. The issue with that is that Chicago would want something of value back, but the Yankes farm system isn't exactly loaded with talent.