France Vs Holland
Japan vs Italy
Croatia vs Canada
Australia vs Germany
Kazakhstan vs Switzerland
Serbia vs Usa
Belgium vs Hungary
Spain vs Great Britain
so many important absences, for me the most interesting match is Australia vs Germany A.Zverev vs Kyrgios
France, Italy, Canada, Australia, Kazakhstan, USA, Belgium, Spain that's my opinion.
Don't know who will play for other countries. But between Croatia and Canada I don't see how Canada could win this. Raonic is not playing. Pospisil is playing but he was sick and wouldn't play today if Polansky didn't get injured. So in my opinion Canada has one solid single player Shapovalov who doesn't know how to play on clay. Lost all matches on clay last season. They have also one good doubles player Nestor.
On the other hand Croatia has Coric, Cilic & Dodig for doubles. I see Canada taking 1 point max and that one should be Shapovalov win over Galovic later today or maybe doubles tomorrow if Croatia has 2:0 and selects B team.
Not to mention home advantage.
Up to now, only 2-0 won by Kazakhstan and Belgium and probably the United States.
All the other matches are on 1-1!
the double could be decisive in many matches