Barcelona coach Ronald Koeman says the club's problems have been masked by the presence of Lionel Messi.

Koeman saw Messi leave for PSG this past summer and admits the Argentine's departure has left the club exposed.

"Lionel Messi has glossed over everything at Barcelona," Koeman told Voetbal International. “He was so good and he won. Of course he had good players around him, but he made the difference. Everyone seems better because of him. This is not a criticism, but an observation.

“I knew how good he is, but it's still nice to see it up close every day. Everything you would like to teach a football player, in recognising situations, in the assumptions of the ball under pressure, in ball speed, in finishing; with Messi everything is a ten. Not normal, not normal!

"When we did a finishing drills during training, there were sometimes players who started to shoot an easy ball, a bit of fooling around. But with Messi everything was: boom, boom, boom, boom. Never frills, everything functional.

“He was an example for the players. When we won the Copa… Messi took so many trophies, bigger than this one, but you saw that the Copa del Rey really did something for him this time. With those young players there, he saw the future of the club. All those guys wanted to take a picture with him, I've never seen anything like it. He was and is that big. The fact that he is not here now was a shock to the whole city."