Following their best start to a Bundesliga season in six years, resurgent Schalke are relishing hosting Bayern Munich, whose coach Carlo Ancelotti has faced criticism from one of his former mentors, on Tuesday.

Schalke have won three of their first four league games, including beating Champions League contenders RB Leipzig, under new coach Domenico Tedesco, who is only 32.

They are fourth in the table, one place below Bayern, who have an identical record of three wins and a defeat but are third on goal difference.

A win in Gelsenkirchen could put Schalke top as current leaders Borussia Dortmund play Hamburg on Wednesday, the same day second-placed Hanover are at Freiburg.

But Tedesco is warning his side to not get ahead of themselves.

"If you go into the game thinking that you want to lead the table, then you forget all the small steps you need to take," said the Schalke coach.

Nevertheless, there is an air of confidence around the Veltins Arena.

"If you play against Bayern you have to step out with your head held high -- which we can now do," said Schalke midfielder Leon Goretzka, who hit the winner in Saturday's 2-1 victory at Werder Bremen.

Goretzka, 22, shone at the Confederations Cup in the summer when Germany lifted the trophy but is out of contract next June and likely to be on Bayern's radar.

Bayern hammered Mainz 4-0 on Saturday after suffering a shock league defeat at Hoffenheim a week earlier. Their challenge is proving it was not a one-off.

"We must confirm that this is not unique," said Arjen Robben, who scored Bayern's second goal against Mainz.

The biggest threat facing Ancelotti and Bayern's sporting director Hasan Salihamidzic is keeping the squad together amidst obvious cracks.

Hot-shot striker Robert Lewandowski, who has now scored 82 goals in 100 league games for Bayern, has criticised the club's spending policy.

Robben slammed the team's performance for struggling to break down 10-man Anderlecht before winning 3-0 in the Champions League last midweek. And winger Franck Ribery threw his shirt at the bench in a temper after being substituted in that same game.

Now Ancelotti has been criticised by his former coach Arrigo Sacchi.

"It looks as though some changes would do Bayern good," Sacchi, one of Italy's former top coaches, told German broadcaster Sport1.

"One gets older and loses the passion and the absolute will -- that's life," added the 71-year-old in a thinly-veiled attack on Ancelotti.

"I have the impression that the enthusiasm of the team has been lost."

The 58-year-old Ancelotti is one of Europe's most successful coaches having won three Champions League titles with AC Milan and Real Madrid.

As a player, Ancelotti won the European Cup under Sacchi in 1989 and 1990 at Milan.

Meanwhile, former Mainz boss Martin Schmidt has been appointed by Wolfsburg to replace Andries Jonker, who was sacked following Saturday's 1-0 defeat at VfB Stuttgart.

Schmidt will get an early chance to assess his new charges as they host Bremen on Tuesday evening before going to Bayern on Friday.

Fixtures (all times 1830 GMT unless stated)

Playing Tuesday

Borussia Moenchengladbach v Stuttgart (1630), Schalke v Bayern Munich, Augsburg v RB Leipzig, Wolfsburg v Werder Bremen

Playing Wednesday

Cologne v Eintracht Frankfurt (1630), Hertha Berlin v Bayer Leverkusen, Freiburg v Hanover 96, Hamburg v Borussia Dortmund, Mainz v Hoffenheim