Juventus must improve despite Lyon win, says goalkeeper Gianluigi Buffon

Juventus goalkeeper Gianluigi Buffon insists his side must improve if they want to be serious Champions League contenders this season following a .

According to , the Italian champions remain top of Group H, ahead of Sevilla on goal difference, after substitute Juan Cuadrado scored the decisive goal in the 76th minute.

But Juve, who played most of the second half with 10 men after midfielder Mario Lemina's dismissal for two yellow cards, owed victory to skipper Buffon.