Martin Keown has told the Daily Mail that Everton striker Romelu Lukaku often looks like he lacks motivation.
Lukaku has earned plenty of plaudits for his performances for the Toffees this season, but Keown feels that there is still more to come.
The former Arsenal defender says that Lukaku is too inconsistent at the moment, and he wants to see him at full throttle for full games in the future.
"I think Romelu Lukaku is a player who sometimes lacks motivation," Keown said. "You see moments when he’s like a tiger and others when he looks more like a pussycat.
"Roberto Martinez paid a lot of money for him and has shown a lot of belief in him, but he’s got to keep creating goals for him. If he wants to succeed he’s got some way to go. We’re seeing the start of it at the moment, but even in the space of one match his performance level can be so varied. You want to see that fire from the off.
"I would like him to be more demanding and ask for the ball to be played into him. Everton passed it around for fun last season, but a lot of it sideways. Their midfielders should play the ball forward more, James McCarthy especially. He’s an excellent player and is very important to Everton, but he needs to express himself more."
Lukaku's work-rate has been brought into question before, but there have been few complaints from Everton supporters about his performances this season.
The Belgian international has dominated defences on frequent occasions, and he has scored seven goals in his first 10 appearances.
That represents an excellent return but, at the age of 22, Lukaku still has plenty of time to develop his game and make the improvements which Keown suggests he needs to.
Lukaku's next match comes against Manchester United on Saturday, and the powerful forward will be hoping to put in a 90-minute performance against Louis van Gaal's side.