Italy are first in Group C but hope to remain top when the World Cup Qualifiers are concluded, as the 10 group winners in the European qualification are the only teams guaranteed a place at Qatar 2022.
The Azzurri drew 1-1 with Buglaria on Thursday and are first with 10 points after four games, but Switzerland sit second with maximum return from their two first matches.
The EURO 2020 winners prepare to face their biggest rivals in Group C on Sunday, as they travel to Switzerland, before facing Lithuania on Wednesday September 9.
In Europe there are 55 nations trying to qualify for a place in the 2022 World Cup, with 10 groups of either five or six teams.
The winners of each group will automatically qualify for the Finals in Qatar next year, but the three remaining places will be decided through the play-offs.
The runners-up in every group plus the two highest-ranked group winners from the UEFA Nations League in 2020-21 are competing for the three places in the prestigious competition.
The Europan qualification will then have three different semi-finals and a Final, playing for a place at Qatar 2022.