Giuseppe Rossi was left out of Italy's World Cup squad because taking him to Brazil so shortly after an injury would have been too risky, coach Cesare Prandelli said.

Prandelli said he was surprised by the amount of controversy the decision had generated and insisted that the U.S. born Fiorentina forward knew from the start that he was unlikely to make the final 23.

"I didn't expect such a big controversy, it has caused some difficulties and I would like to clear up what has happened," Prandelli told reporters ahead of Wednesday's warm-up friendly against Luxemburg.

"I feel a great responsibility towards my squad, to the supporters, to Fiorentina, and taking him to Brazil was a risk that did not make sense to me, although it would have been easier to have picked him.

"I told him that he had not completed the healing process."

Rossi, who only returned to action in early May after suffering his latest knee injury in January, was included in Italy's provisional 30-man squad and played for more than one hour against Ireland in Saturday's friendly.

"I met Rossi at Covericano (Italy's training camp) before announcing the (provisional) list of 30. I came to talk to him, to warn him that he had only played a few minutes since he had recovered from his injury.

"I intended to tell him he wasn't among the 30, but I thought he could give an example to everyone else, a beautiful story to tell. At that moment, I told him he wasn't among the 23, I repeated it twice."

Prandelli added: "Before the last game, I called him and told him that from a physical point of view, some of the test results were good and others less good.

"I told him I wanted to see a striker who played as a striker, and I wanted to see that something extra, but I didn't see what I wanted to see."

Rossi's unlucky run began when just missed out on being selected for the 2010 World Cup by coach Marcello Lippi.

The following year, he suffered an anterior cruciate ligament injury while playing for Villarreal in a Spanish league match against Real Madrid in 2011.

He fought desperately to be fit again in time Euro 2012 only to re-injure the knee in training the following April, causing him to miss the tournament.

He made an excellent comeback with Fiorentina this season, scoring 14 goals by early January to make him Serie A's leading scorer.

However, he then suffered a less serious injury, a second degree sprain to the medial collateral ligament, in the same knee which sidelined him until the start of last month.