What does "I probably can’t hit the ball out of the Fenway" mean. The Fenway.?

Fenway is just the name of a baseball park. It's home to the Boston Red Sox and it also happens to be the oldest major league ballpark. I think that it is a little easier to hit home-runs there than other ballparks so he's saying that if he can't hit one outta the park there then he can't do it at all.