Veteren player making a high salary not doing well in the season. Trade for him and hope a change in scenery helps him out. Sounds vaguely similar to the same position Liriano was in.
Granderson is hitting .222/.315/.476 with an OPS of .791 in May. There's reasons to believe he can turn it around. He's old, but we'll have him for what? 4 months if we do the trade this week? He's expensive, but that gives us leverage more than anything. Mets can eat a bit of salary, or we can take on a bit more and get prospect capital in return.
It's not the worst idea in the world. We get a left handed bat in our lineup who has a good track record.