It was Frank Rijkaard who gave the teenage Messi his first opportunity in the Barcelona first team and the Argentine has not forgotten that.

"To be honest, all the coaches I've had since I arrived in the Primera Division have taught me something," Messi said in an interview with MBC. 

"But I think the most important in my career was Rikjaard.

"If he had not trusted me and decided not to put me in the first team - at first to train and late to actually play - maybe I wouldn't have made it to the first team at all.

"I have always said that he's a very important person for me, because he had confidence in me, put me in at the right time, picked me to play for the first team and that was very important for me."

Source: sport-english.com.

Rijkaard is still a very big coach in Barca's history. He was instrumental in reviving and taking the team from ground zero to what it is today- Messi's attribute is a mild confirmation. I love his style, but unfortunately, he left Barca in extra-football related circumstances.

is he retiring?