Lionel Messi has admitted that it was "extremely difficult to accept" that he would have to leave Barcelona over the summer, with the Catalan outfit unable to renew the Argentina international's contract.

Barcelona's deep financial problems meant that they could not afford to hand Messi a new deal, and the Argentina international left Camp Nou on a free transfer for Paris Saint-Germain.

Messi has conceded that he 'did not expect' to leave Ronald Koeman's side and had planned on finishing his career with the La Liga giants before the depth of their off-the-field issues became clear.

"I didn't expect it at all," Messi told France Football. "In my head, I was going to go [back to Barcelona], sign and start training straight away.

"I thought that everything was set and I just needed to sign it. But when I got there, they told me that it wasn't possible anymore. They told me that I couldn't stay and that I'd have to find a new club because they couldn't renew my contract. It changed my plans.

"It was extremely difficult to accept. To think that we were going to have to leave our home, the family were going to have their routines turned upside down, the kids were going to have to change schools and come with us to a completely new place.

"It was the first time that this had happened in my career. I had decided that I was going to end my career with Barcelona. It was difficult, but we passed the test together. A lot of things went through my mind, but I had no choice but to leave."

Messi has only scored once in five appearances for PSG this season, with the effort coming against Manchester City in the Champions League at the end of September.