Juventus defender Giorgio Chiellini has admitted that his side have work to do to get back to their best.

The Italian outfit claimed a vital victory over Sporting Lisbon in the Champions League on Wednesday, with striker Mario Mandzukic heading an 84th-minute winner.

The result means that the Bianconeri sit second in Group D, three points above Sporting, whom they face again in two weeks' time.

Juve are currently five points adrift of leaders Napoli in Serie A, and Chiellini believes that the team must work hard to get back on track.

"It was a tough game but we knew it would be, because Sporting are a very good side," the Italian international told uefa.com.

"We earned three important points and now everything will be decided in Lisbon - we are ready for it.

"We didn't want to concede goals but I'm happy that we reacted well, showing that we wanted these three points until the final whistle. Right now we have to improve many things, we are not as balanced as we were in the past, but we have time to grow."

Juventus travel to 13th-placed Udinese on Sunday evening.