Croatia coach Niko Kovac warned on Saturday that the qualifier against Italy will have to be called off if the pitch in Milan does not improve.
The 2016 Euro qualifying match is scheduled to kick off on Sunday at 8:45 p.m. local time but Milan has been hit by flash floods and torrential rain, forcing both teams to abandon their planned training sessions at the San Siro.
"If the pitch remains in these conditions, the game can't go ahead," Kovac said. "The ball doesn't bounce, it would be like a game of water polo."
Italy and Croatia are level at the top of their group, having won their opening three matches.
"Let's hope the weather improves. For a good match the pitch has to be at its best," Italy coach Antonio Conte said.
Conte has said the match will be a true test of how far Italy has progressed since he took over in July following a dismal World Cup, and Italy captain Gianluigi Buffon agreed.
"Tomorrow will not be a game like any other, because these groups are made up of prestigious teams and minnows," the goalkeeper said. "It's clear that this will be one of those matches which lights up interest. We are going into it with a certain curiosity to measure ourselves up against Croatia.
"We have a lot of humility but also a lot of ambition, because we are Italy and our football history speaks for us. We want to impress tomorrow, and convince ourselves as well as the public that the Italian team is still alive and kicking."
Despite Italy's group exit in Brazil, hope is growing that the Azzurri can be realistic title challengers in 2016.
"We have to proceed carefully in every sense, because we're coming off the back of a burning disappointment and we should never forget that disappointment because it will give us extra strength to move forward," Conte said.
"We're moving forward in steps. We should never lack ambition and we need to show that we have our feet firmly on the ground. We'll qualify first and then in that month try and create a war machine."
Mario Balotelli withdrew from the Italy squad earlier in the day, along with Juventus defender Angelo Ogbonna.
Balotelli had been called up for the first time under Conte, despite his poor form, but the Liverpool striker strained his lower back and adductor muscles.
"Mario had this inflammation in the groin and couldn't train," Conte said. "So it was useless to keep him with us. Yes, I liked him, like the others I hadn't seen before."