Believe he can still play a part. People have written him off very, very quickly. If I remember right, he did fine in his first few games. I remember him being impressive against Sevilla and chipping in with an assist for big Erl against the Rags.
I think that red card was a big knock to his confidence and he hasn't looked great since then, but we also have barely seen him. It's similar to how a lot of people have written off Phillips despite him playing about 20 league minutes.
Not saying he's going to turn into a world beater overnight, but I don't think he's just some useless idiot either, he's a professional player working under the greatest manager around, training and learning more each day, and I think he's at least capable of coming into games against teams lower down the table and getting more experience and understanding of how the team works and what he needs to do to be part of it.
We've had a lot of players look a bit crap early on in their time here and gradually improve. I think one of Zinny's earliest games was a league/FA cup game where he looked absolutely dreadful and couldn't keep hold of the ball, but he got far better after that. No reason Gomez can't do the same.