'Chelsea need a striker to challenge'

Much has been made of Alvaro Morata's form over the last year, but according to the Dutchman the club still need another to bolster their ranks to compete. 

"I think every club that is going to challenge for the Premier League needs three strikers," Hasselbaink said. 

"For me they [Chelsea] still have a gap to close on Man City, but they are improving and if they can keep on improving they can hopefully catch them.

"[Sarri] has changed the way they play totally. They now play more in the defensive third of the opposition. They have the ball 60 or 70 per cent of the time - that was totally different last year.

"You see smiles on the players' faces again and they're playing attractive, attacking football."