Adriano recently played for his country in a World Cup qualifier and announced shortly after the game that he was taking a leave of absence and not rejoining the three-time defending champions and Serie A leaders Inter Milan for the final stretch of the campaign.

"I was the first to be stunned by what happened," said Dunga in an interview with Gazzetta dello Sport.

"During our last stage, I saw him happy and he was having fun.

"I could not have expected anything like this.

"He is a lad that is going through a time of great confusion.

"Football of today involves a lot of pressure and he has not been able to deal with it.

"But he will soon miss this world and I am certain he will return."

It has been reported that Inter are set to terminate the 27-year-old's contract, which runs until June 2010.