Pep Guardiola has described Xabi Alonso as one of the best midfielders he has ever seen after the Bayern Munich player confirmed his impending retirement.
Alonso, 35, will end his career at the conclusion of the season following his announcement on Thursday.
Manchester City boss Guardiola brought Alonso to Bayern in 2014 and spent two seasons coaching the former Liverpool and Real Madrid star prior to his move to England.
Guardiola is in no doubt over how highly Alonso should rank in the world game and is certain the World Cup winner with Spain will end up as a manager.
"We were rivals, big rivals when he was at Real Madrid," Guardiola said ahead of City's FA Cup quarter-final match against Middlesbrough on Saturday.
"After that I was so lucky to have him in Munich.
"How the people speak about him - all the managers that he had in his career - is like a human being. One of the best midfielders I've ever seen in my life.
"He will come back soon as a manager. I bet, wherever he wants, he will become a manager and will be good.
"He understands the game and has curiosity to understand the game. He knew during the weeks what we would have to do to win the next games, to beat them. He already had the curiosity to know.
"I love to work with these kinds of people. Normally that happens with the midfield players - in Barcelona, with Javier Mascherano, Sergio Busquets, here with David Silva and Fernandinho.
"They are involved in what you are doing and why you are doing it. It's marvellous as a manager to have these kind of players."