It should be said that Wesley Snipes does very well as Bobby Rayburn; he makes the connection with the audience that De Niro fails to. Snipes can be a bit stiff and dreary in macho action roles, but when, as here, he gets the chance to play some raw nerves, he's immediately engaging, and he shows a surprisingly large emotional range. Several other actors do sharp, helpful work--Ellen Barkin brings her feral friskiness to the smallish role of a sports reporter, and Charles Hallahan has a few strong minutes as Gil's scared, befuddled old teammate.
In terms of talent, The Fan's director Scott is to Scorsese about what Roger Corman is to Orson Welles. This needn't be entirely pejorative--great though Welles and Scorsese indisputably are, both have made hollow, ponderously overthought work, and pop wise guy though he is, Corman is usually inventive and fun. When working from lively scripts, Scott has done amusing work, too--the first half of The Hunger, for instance, and most of True Romance and Crimson Tide. But Scott's headlong, frenzied visual shorthand has lent itself with equal frequency to such distilled evil as Top Gun. The Fan is of the latter category. It's such a shoddy, charmlessly eager-to-please penny dreadful that it doesn't even work as camp.
Indeed, it would be unworthy of even adverse notice if it weren't for the presence of De Niro as star. He's a great actor, and even the worst and laziest work of a great actor deserves study. What can I say, I'm a fan.