Victory over Lazio on Wednesday could be Juventus' final step to a fifth successive Scudetto, says Massimiliano Allegri.

Juve extended their advantage at the Serie A summit to nine points by defeating Palermo 4-0 after second-placed Napoli suffered a 2-0 loss at Inter a day prior.

Allegri's side need, at most, seven points in order to be crowned champions for a fifth straight season, and the coach is confident that overcoming Lazio will play a crucial role.

"The only numbers that interest me relate to mathematics – we need seven points, hopefully fewer after tonight, although it is unlikely that Napoli will not beat Bologna," said Allegri.

"We must be careful against Lazio. The three points would make a nice leap forward, probably the final one, to the fifth title. A fifth successive Scudetto would represent an extraordinary achievement.

"They are fighting for the Europa League and are a dangerous opponent, not to mention that we lack [Alvaro] Morata to a suspension. We're facing a Lazio side who come into the game following consecutive victories without conceding.

"We've got a decent advantage over Napoli, but nothing's guaranteed until the mathematics state otherwise.

"Everyone's praising us, but we still haven't won anything as it stands."

Claudio Marchisio sustained a cruciate ligament injury against Palermo that has ruled him out of contention for Italy's Euro 2016 campaign, and a statement released by Juve on Tuesday confirmed that the midfielder's surgery had been a success.

"I spoke to Claudio, he was pretty calm. It is a serious injury, but fortunately in September he will be back in training," the coach said.

Allegri added there have been no discussions about a new contract with Juve, but reiterated his intent to remain.

"I have said again and again we will not meet this week, but at the end of the season," said Allegri.

"With the club there are no problems. If I wanted to leave I would have said a month ago, to allow Juventus to find another coach and myself to find another team."