I think I've figured out Warner's problem. He's an alien. Apparently his species secretes some kind of slippery substance which makes it difficult to hold onto items; footballs being the items germane to this discussion.
It's the only thing I can think of to explain why he not only has so much trouble hanging onto the ball himself, but why the guys he throws to can't hang onto the ball either. Pope today, Fitzgerald in games past... it just makes sense. He's wearing the gloves to try to stop the secretion, but it's just not working. Probably they secrete more and more of the stuff as they get older.