Based on what? YouTube clips, his performances in Bundesliga, a few games for Belgium?
Don't get me wrong I think KDB is great and will be great for us, but Nasri is proven in the PL & has played well in the few minutes he's had so far. What would it say to him if he was immediately behind KDB? When he's come on he's worked hard and showed his worth, for me it would be pretty harsh for him not to start.
Saying that if KDB does start I'll be excited to see how he gets on. Both are great players & we'll still be a strong 11 whomever plays.