The Real Madrid playmaker had been struggling with a foot injury since the opening-day loss to Brazil, but both he and Mario Mandzukic will be in the starting line-up in Manaus
Croatia coach Niko Kovac says Luka Modric is "100 per cent fit" to face Cameroon on Wednesday, and insists his side will go for all three points in the crucial Group A clash.
The loser of the match will be the first team eliminated from the World Cup as both were defeated in their first outings and are now four points adrift of Brazil and Mexico following their draw in Fortaleza on Tuesday.
Modric was in some doubt for the game in Manaus after picking up a foot injury in the opening-day defeat to Brazil, but Kovac says he will be ready to help his team try to take all three points.
"Luka is going to be 100% fit," he said. "He did well Tuesday and Monday in training, no problems there. He will be 100% match fit."
"We know what this match means to us and Cameroon. We’ve come here to play football and win three points because it means so much to us. Let’s not dwell on the maths, let’s focus on the game and the three points.
"Cameroon have to win to have any chance, and so do we. We could even play for a draw but we want three points, we will play our game.
"They are a strong team with high quality, but we want to impose our style of play. It is the same as I said after Brazil: if we play the same way I don’t see why we wouldn’t progress. We will fight and I am convinced that we are going to win the game."
Mario Mandzukic will return to the Croatia team after suspension kept him out of his country's first match, and Kovac is delighted to welcome him back into the fold.
"I am very glad that Mario is with us, his skills are well known," he added. "Any coach would be satisfied to have such a player in their ranks, and I am. I know he will inject some energy into this match and lead us to victory, I hope."
And Mandzukic himself is raring to get his tournament up and running: "I’m very glad to be back, I could hardly wait for the day to arrive. I worked hard in training, this is a very important match for me and for all of us. We are ready and I cannot wait for it to start.
"There's not much pressure because we came here to win games. We always knew that we would have to beat Cameroon and Mexico and this has not changed. We want to win both and we are ready. We are positive, I am certain that we can take the first step by winning the game."