2018 World Cup qualifier: Gianluigi Buffon smells wind of change as Spain arrive without Iker Casillas

Piedmont: Gianluigi Buffon admits the prospect of losing his status as Italy`s undisputed number one goalkeeper has been brought closer by the arrival of Spain ahead of the sides` 2018 World Cup qualifier on Thursday.

At 38 years old, Buffon remains pivotal to an Azzurri side that upset Euro 2016 predictions by reaching the quarter-finals, where only a dramatic 6-5 penalty shootout defeat to Germany ended their hopes.

Buffon is expected to remain with Italy at least until the World Cup, but the game in Turin has prompted him to wonder exactly when his sterling career will come to an end.

Coach Giampiero Ventura handed teenage AC Milan goalkeeper Gianluigi Donnarumma his debut during the second half of a 3-1 friendly defeat to France last month.

And Iker Casillas`s omission from the Spain squad by newly-appointed coach Julen Lopetegui has made Buffon realise he cannot go on forever.

"The fact he`s not here is very strange, but it`s also a signal for me," Buffon told media of Casillas, 35.

"We`re running out of time, but that`s normal. But I`m fine with that. Inside of me I know my sporting career has to come to an end. Until that happens, I`ll enjoy every moment."

Set to earn his 164th cap, Buffon will edge one closer to former Real Madrid goalkeeper Casillas`s 167-cap record for a European footballer, which he shares with retired Latvian Vitalijs Astafyevs.

After opening their World Cup qualifying campaign with a 3-1 win against Israel in Haifa last month, Italy host Spain at Juventus Stadium fully aware the result will be key in deciding which team clinches top spot in a Group G that also includes Albania, Israel, Liechtenstein and Macedonia.

"This is an important match that will have consequences in terms of who qualifies for the World Cup," said Ventura, who succeeded Antonio Conte after he became manager of Chelsea in the summer.

"But we won`t win this game if we play at 60 percent of our capacity."As well as dropping Casillas, Lopetegui has instigated a number of other changes to a Spain squad that won the World Cup in 2010 and the European Championship in 2008 and 2012 but has disappointed at the last two major tournaments.

Spain put eight unanswered goals past Liechtenstein in their opening qualifier in Leon, where Chelsea forward Diego Costa was one of three players to hit a brace.

Ventura was quick to underline the qualities of his own, new-look squad but warned: "I believe that, tactically, Spain have taken a step forward. But what most worries me is how mentally ready they look."

Costa is expected to be given the nod to play up front on Wednesday ahead of Real Madrid striker Alvaro Morata after Lopetegui said: "Tomorrow Costa will play .... this will be a key game for us and should fully test our ability to impose our game. But we`re here for a result."

Buffon spent two seasons playing alongside Morata at Juventus and is aware of the striker`s threat. But he added: "If he doesn`t play, it just means Spain will replace him with another top-class striker."

Buffon has called on Italy to "keep their feet firmly on the ground" as they aim to prove their Euro victory in June was no fluke.

"Spain suffered by their defeat to us but now they`ve recovered from their elimination -- as we have," he said.

"We have to keep our feet firmly on the ground, stay humble and above all try to recall the extent to which we motivated ourselves to go out and win this game, and then reproduce it.

"We`re 18 months from the World Cup and we should be lucid enough to know how important this game is."