Current world champions France have had to stay at their training camp rather than their usual pre-match base after hotel staff tested positive for Covid.
That means their trip to the Stade de France is over an hour rather than 20 minutes.
"We're adapting. With several Covid cases at the hotel it was unthinkable to stay there," coach Didier Deschamps said.
"It's not ideal as our journey to get to the stadium will be longer but we're comfortable at Clairefontaine."
He also warned Ukraine will be a lot better than the Covid-ravaged side who lost 7-1 to France in an October friendly.
"It's not the same team coming this time," said Deschamps.
"They are very good technically, they play a possession game and combine a lot on the flanks with their full-backs."
Are Portugal better without Ronaldo?
Portugal v Azerbaijan (19:45 GMT)
Read this piece from Marcus Alves discussing whether Portugal are actually better without 102-goal legend Cristiano Ronaldo.
With players like Bruno Fernandes, Bernardo Silva, Diogo Jota and Joao Felix they have done well in games he has missed recently.
.Copyright: .
LINE-UPS
Portugal v Azerbaijan (19:45 GMT)
Three Manchester City players and three from Wolves in the Portugal team. Cristiano Ronaldo too.
Portugal: Lopes, Joao Cancelo, Dias, Domingos Duarte,
Nuno Mendes, Bernardo Silva, Joao Moutinho, Neves, Pedro Neto,
Andre Silva, Ronaldo.
Text or tweet in any thoughts you have on tonight's games.
Republic of Ireland
Team selector
This was the most popular team picked on our Republic of Ireland team selector.
Eight of the 11 are in the team. Shane Duffy a notable casualty from the actual Irish line-up.
BBC SportCopyright: BBC Sport
Republic of Ireland - Team selectorImage caption: Republic of Ireland - Team selector
Republic of Ireland team
Serbia v Republic of Ireland (19:45 GMT)
The Republic of Ireland start both Seamus Coleman and Matt Doherty. Aaron Connolly has recovered from injury to start up front.
Anderlecht midfielder Josh Cullen gets a start.
Mark Travers gets his chance in goal with Darren Randolph and Caoimhin Kelleher injured.
BBC SportCopyright: BBC Sport
Republic of Ireland teamImage caption: Republic of Ireland team
BBC SportCopyright: BBC Sport
Serbia teamImage caption: Serbia team
Post update
Turkey 4-2 Netherlands
ReutersCopyright: Reuters
There has already been one game today - and it was a thriller.
Turkey captain Burak Yilmaz, 35, scored a hat-trick in a 4-2 win over the Netherlands in Istanbul.
Hakan Calhanoglu scored their other - to make it 3-0.
Davy Klaassen and Luuk de Jong gave the Dutch hope with two quickfire goals before Yilmaz got his hat-trick.
Memphis Depay also had a penalty saved.
How does it work?
The 10 group winners in qualifying will secure their place at the tournament while the 10 group runners-up will go through to the play-offs, along with the two best Nations League group winners who do not finish in the top two of their World Cup qualifying group.
The 12 play-off teams will be drawn into three separate play-off paths, each of which will comprise semi-finals and final, with the three winners heading to Qatar.
Post update
We'll be covering mostly the Republic of Ireland, Portugal and France games here.
Live Reporting
Emlyn Begley
All times stated are UK
Disruption to France's plans
France v Ukraine (19:45 GMT)
Current world champions France have had to stay at their training camp rather than their usual pre-match base after hotel staff tested positive for Covid.
That means their trip to the Stade de France is over an hour rather than 20 minutes.
"We're adapting. With several Covid cases at the hotel it was unthinkable to stay there," coach Didier Deschamps said.
"It's not ideal as our journey to get to the stadium will be longer but we're comfortable at Clairefontaine."
He also warned Ukraine will be a lot better than the Covid-ravaged side who lost 7-1 to France in an October friendly.
"It's not the same team coming this time," said Deschamps.
"They are very good technically, they play a possession game and combine a lot on the flanks with their full-backs."
Are Portugal better without Ronaldo?
Portugal v Azerbaijan (19:45 GMT)
Read this piece from Marcus Alves discussing whether Portugal are actually better without 102-goal legend Cristiano Ronaldo.
With players like Bruno Fernandes, Bernardo Silva, Diogo Jota and Joao Felix they have done well in games he has missed recently.
LINE-UPS
Portugal v Azerbaijan (19:45 GMT)
Three Manchester City players and three from Wolves in the Portugal team. Cristiano Ronaldo too.
Portugal: Lopes, Joao Cancelo, Dias, Domingos Duarte, Nuno Mendes, Bernardo Silva, Joao Moutinho, Neves, Pedro Neto, Andre Silva, Ronaldo.
Azerbaijan: Mahammadaliyev, Medvedev, Badalov, Badavi Huseynov, Krivotsyuk, Abbas Huseynov, Mahmudov, Mustafayev, Salahli, Emreli, Ghorbani.
Get Involved
#bbcfootball or 81111 on text
Text or tweet in any thoughts you have on tonight's games.
Republic of Ireland
Team selector
This was the most popular team picked on our Republic of Ireland team selector.
Eight of the 11 are in the team. Shane Duffy a notable casualty from the actual Irish line-up.
Republic of Ireland team
Serbia v Republic of Ireland (19:45 GMT)
The Republic of Ireland start both Seamus Coleman and Matt Doherty. Aaron Connolly has recovered from injury to start up front.
Anderlecht midfielder Josh Cullen gets a start.
Mark Travers gets his chance in goal with Darren Randolph and Caoimhin Kelleher injured.
Post update
Turkey 4-2 Netherlands
There has already been one game today - and it was a thriller.
Turkey captain Burak Yilmaz, 35, scored a hat-trick in a 4-2 win over the Netherlands in Istanbul.
Hakan Calhanoglu scored their other - to make it 3-0.
Davy Klaassen and Luuk de Jong gave the Dutch hope with two quickfire goals before Yilmaz got his hat-trick.
Memphis Depay also had a penalty saved.
How does it work?
The 10 group winners in qualifying will secure their place at the tournament while the 10 group runners-up will go through to the play-offs, along with the two best Nations League group winners who do not finish in the top two of their World Cup qualifying group.
The 12 play-off teams will be drawn into three separate play-off paths, each of which will comprise semi-finals and final, with the three winners heading to Qatar.
Post update
We'll be covering mostly the Republic of Ireland, Portugal and France games here.
Our colleagues in Wales will be covering their game against Belgium on their live text.
We'll bring you updates from there and all the other games too.
The 19:45 GMT games...
Serbia v Republic of Ireland
Portugal v Azerbaijan
France v Ukraine
Belgium v Wales
Finland v Bosnia
Estonia v Czech Republic
Gibraltar v Norway
Latvia v Montenegro
Cyprus v Slovakia
Malta v Russia
Slovenia v Croatia
The road to Qatar begins....
(in Europe)
607 days until the 2022 Fifa World Cup in Qatar begins.
Today the European qualifiers get under way. Asia and South America have already started.
So who's in action today and how does it all work?