The Azzurri need three points to consolidate second place in Group G behind Spain and stay safely clear of third-placed Albania as they look to make it to the finals in Russia next year.
Giampiero Ventura's side were outclassed by the 2010 world champions, inspired by Real Madrid midfielder Isco, as they lost 3-0 at the Santiago Bernabeu on Saturday.
Tuesday's challenge against Israel at the Mapei Stadium in northern Italy has now become all the more important as the four-time world champions look to regain confidence with a two-legged play-off now looking increasingly likely if they are to reach the World Cup.
Napoli forward Lorenzo Insigne added: "To get to the World Cup we need to remain united."
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Israel -- seven points behind Italy -- are coming off a 1-0 defeat to Macedonia, their fourth of the campaign.
But Ventura has defensive worries.
Giorgio Chiellini is still out with a calf problem along with Leonardo Bonucci, who picked up a booking on Saturday, and Leonardo Spinazzola, injured in the last few minutes in Spain.
New Chelsea recruit Davide Zappacosta was hastily called up to training in Florence on Sunday as Ventura looks to pull together a makeshift defence.
Meanwhile, AC Milan's teenage goalkeeper Gianluigi Donnarumma could take the place of veteran captain Gigi Buffon, 39, between the posts.
"It was a defeat against a side with great quality. We did some good things, others bad, it mustn't wipe out the good work done up until now," Darmian said after the defeat.
"We go home with quite a heavy defeat, but we look forward."
The defeat was Italy's first loss in either World Cup or European Championship qualifying since September 2006, a run of 56 matches.
Tuesday's qualifier against Israel will be followed by games against Macedonia in Turin and Albania away in October.
The last time Italy had to go through play-offs was in 1997 on the road to the 1998 World Cup in France.
Italy were handed a boost ahead of the Israel match, however, with news that their captain Eran Zahavi had suddenly decided to end his international career after being angered by booing from the home crowd.
In response, Zahavi threw his captain's armband to the ground, prompting Israel's federation to suspend him for an undetermined period.
"I can't stand it anymore," Zahavi, who plays professionally for China's Guangzhou R&F, told Israeli newspaper Yedioth Ahronoth after his decision on international retirement.
"We are in a country that doesn't know how to honour its great athletes, so I prefer to leave. It's unbelievable that the fans boo their team. That doesn't happen anywhere else in the world.