The Scots have been hit with six call-offs ahead of Friday's World Cup qualifier after Scott Brown, James Forrest, Lee Wallace, Danny Fox, Gary Caldwell and Liam Bridcutt were all forced to pull out of the trip to Zagreb.
Boss Gordon Strachan will have no option but to rely on a group of players who are not blessed with a great deal of experience at international level as the Scots seek their first win of the qualifying campaign.
But McCall believes those given the nod should approach the match without any fear and make the most of the opportunity.
He said: "Prior to coming here, I thought to myself what our mindset will be when we meet up. Is it a case of let's go and play some good football and give the young boys a go and it doesn't really matter what the score is as long as they get good experience?
"Obviously you want to win every game you go into but is it damage limitation? Or is it just go and be the best you can be and maybe not prove people wrong but surprise people?
"I'm sure the majority of people across the world and even in Scotland are looking upon this as a really difficult tie, which we know it is. But I think the mindset is just to go out and be the best you can be and grab the opportunity.
"If you're making your debut, grab your opportunity. If you've had a few caps, help the people who are coming in. Just try to be positive and put a positive spin on it.
"We know we've not got all of this experience to count upon but sometimes young lads have got to step up and have no fear."
Scotland sit bottom of group A, with just two points and their qualification hopes already over, while Croatia are joint top with Belgium.