Roberto De Zerbi says he loves the passion shown by his latest young signing.

But he is not sure Valentin Barco is ready to stop the “motorcycles” who play on the wing in the Premier League.

Barco delighted fans at the Amex with his second-half performance as a substitute in the 2-1 defeat by Chelsea.

He showed pace, tenacity, a good touch and a willingness to send precise crossfield balls towards the right flank.

Barco went on as left-back after Lewis Dunk suffered a knee injury but De Zerbi would ideally play him further forward.

The head coach said: “Barco makes a difference with his character, with his attitude, with his blood.

“I think he is incredible in terms of his behaviour.

“I don’t know if he is ready yet to play as a full-back.

“When you have the ball, okay.

“But when you have to defend against a motorcycle - because in the Premier League as wingers there are motorcycles with great power - he can be in a different situation.

“I love him because he has passion, a strong character.

“He can sell his personality because he has too much personality.”

Dunk left the Chelsea game at half-time and was due to have a scan yesterday.