Why not just let them fight for the jersey. Henderson should be our No2 now, which should mean all domestic cup comps and then pushing DDG for the starting spot. If DDG needs to be dropped, which I think he doesn't really fear currently, Henderson comes in as a PL proven GK. We do tend to overrate our young players probably more at United than anywhere but in this case, Henderson is proven now and has a legitimate argument given DDG's form to be arguing his case to start for us next season. Competition for places is what we need - you can see it's effect on Shaw - when a young guy comes in it lights a fire under the senior player who has become too comfortable in their position, they either get displaced or push on.