Sykes only has one number, My Name, which was not used in the movie. He's also in the reprise of A Fine Life. So, it's clearly a much smaller singing role, but I think it's well suited to him. That said, I'll reiterate what I said earlier that he'll be fine as Fagin.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson