Agreed, I think our midfield is more reliable without him. Modric used to have an exceptional game maybe once a month, with average to good performances the rest of the time. I'd argue that Dembele plays to a high standard on a more consistent basis than Modric ever did, and this will surely improve the more acclimatised he gets.
Very different player, but Modric made us tick in virtually every game for his last couple of seasons at WHL. He did the simple things very, very well and would still improve our side now. Stick him alongside Sandro, push Dembele up behind the striker and we'd have a frighteningly dangerous midfield. I hope that he buggers off to Russia in the summer though, frankly.
