Antonio Conte’s side had a night to forget last night in the Champions League as they fell to a 3-0 defeat away to Roma.
The Blues’ hopes of qualifying as Group C winners hang in the balance, and they could face the likes of Barcelona and Paris Saint-Germain should they progress to the knockout stages as runners-up.
Morata meanwhile, who started against Roma before he was replaced by Michy Batshuayi 15 minutes from the end, made little impact against the Serie A side.
While recognising Morata’s talent, former Blues striker Cascarino doesn’t think he is as intimidating as Costa – something he feels may be hampering his old club.
“Alvaro [Morata] is a big talent but I wonder if Chelsea are missing the nastiness of Diego Costa up front,” Cascarino told The Times.
“Morata is such an honest player: last night he literally picked up Federico Fazio when the Roma defender fell to the floor.
“I can just imagine Costa shoving Fazio aside if he had been in the same position.
“Morata scores plenty of goals and is a fine all-round player, but Costa was always on the edge; bullying people, fouling or being fouled.
“Perhaps Chelsea as a whole have become nicer to play against. I remember I would pick up opponents in the early part of my career but, by the end, I certainly didn’t.
“I learned that no centre back would do the same for me.”