The Young Roos twice fought back from going behind to level the scores and often looked capable of claiming a win.

But sloppy defence time and again undid all the hard work being done in midfield and attack by gifting the opposition goals and ultimately the winner in the 3-2 thriller.

 “This is a very disappointing loss, though we played a very good game,” said Versleijen.

“We were naive in certain parts of the game. If you make those kind of mistakes at this level, you will be penalised for that and that is what we faced today.

"We created some good chances, we scored good goals, but if you give away the goals, like we did today, at this level, you can never win the game.

“I think Costa Rica took the opportunities and in a certain way we gave them the opportunities, especially the first goal. That definitely made it more difficult for us."

Looking towards the Qantas Young Socceroos final group match against Spain, Versleijen is very aware of job ahead for his team.

He added: “You must have hope. You have three games in the pool and from three games, you must have four points to qualify. We know now what our target is and that is to win against Spain.

“So we have no other choice than find a game plan where we will be able to get a good result against Spain.”

In the other group C match Spain qualified for the Round of 16 with a 2-0 win over Ecuador. The Young Socceroos will play their final Group C match against Spain on Sunday at 8am AEST.