If the ones saying he's not good enough watched him week in week out then fair enough. But those that are slagging this transfer, how many times have they seen him play? There are always some that seems to know about all players we're linked with, try hard to sound smart on the internet and misleading people.
I honestly have only seen him play for Croatia since I don't have time to watch non Chelsea matches, so I really don't know much about him.