Jerry Ferrara: I Believe In Hornacek ... Save the Knicks!

NY Knicks superfan Jerry Ferrara -- aka Turtle from "Entourage" -- insists he's fully behind Jeff Hornacek as the new head coach of his beloved squad.

Sorta.

Check out the clip ... Jerry REALLY wants to love the move -- and even drops a few facts as to why it's a good thing.

But that sigh at the beginning of the clip ...