He told Goal at a ceremony where he was re-signing as an Ambassador for Generation Amazing, 2022 FIFA World Cup's social responsibility programme: "I think we have four favourites. Real Madrid, Barcelona, Manchester City and Bayern Munich.
"The rest of the teams are a step down. But we will see. With the Champions League we never know what will happen."
He said: "Argentina, with Messi, are one of the favourites to win the World Cup. Germany, Brazil with Neymar, Spain - I hope that they can win it. But there are many, many favourites to win this competition."
Xavi went on to talk about Andres Iniesta and stated that he would be happy whatever his former team-mate decided to do regarding his future at Barca, while he thinks Arda Turan probably needed more time to succeed at the club.
The Al Sadd midfielder added: "Whatever he [Iniesta] decides I will be happy for him, he deserves the best. He's one of my best friends in world football and he deserves the best. Whatever he decides will be good.
"It [why Arda didn't make the grade at Barca] depends on his confidence. Sometimes Arda needed time to do well at Barcelona. But in Barcelona sometimes you don't have time.
"You have to compete well from the first moment that you play. So it's not easy at Barcelona."