Luciano Spalletti's side need to avoid defeat against the 2022 World Cup semi-finalists to secure a top-two finish in Group B and reach the last 16.
Croatia probably need a win in Leipzig if they are to progress to the knockout phase.
"You dont feel fear in football, you feel fear when you're diagnosed with an illness, not in football," Bastoni told a pre-match press conference on Sunday.
"We don't have fear for Croatia, we have respect for them."
Italy could be eliminated from the tournament in the group stage for the first time since 2004 on Monday if they lose and Albania beat Spain in the other closing group match.
Even if Spain avoid a shock defeat, a loss would leave Italy facing a nervous wait to find out if they go through as one of the best third-placed teams.
The Azzurri were surprisingly flat in a 1-0 loss to Spain last time out, mustering only one shot on target in a one-sided match.
Spalletti said he would make changes to the starting XI which struggled earlier this week.
"After a game like that there is the notion and there's an idea to change the team a little bit," said the former Napoli boss, whose side are on three points after starting their campaign with a 2-1 win over Albania.
"I probably made mistakes in not mixing things up quicker in terms of the performance we produced but I thought it would've been a gamble to tweak anything.
"Now that we've noticed that there's a bit of fatigue, there's a bit of rust, we certainly will change certain things."
Italy have a more inexperienced squad than when they won Euro 2020, with only six of the 17 players who featured in the final triumph over England three years ago in the squad for the tournament in Germany.
"Despite the fact that many of them are young players and they're involved in an extreme match like this for the first time, I think I've seen the right conduct in terms of going out there to put things right and to show we've learnt a lesson as well," insisted Spalletti.
"We said certain things we weren't able to exhibit against Spain, so we need to walk the walk and leave talk to one side."