"I want to apologise obviously to my teammates and to the club," Messi said in a video posted on Instagram to his 458 million followers.
He was suspended by the Qatar-owned club after failing to turn up for training on Monday, a day after their 3-1 home defeat by Lorient in Ligue 1.
Instead, the seven-time Ballon d'Or winner travelled to Saudi Arabia without PSG's permission to fulfil commitments as part of a contract with the country's tourist office. "I honestly thought we were going to have the day off after the match as had happened in the previous weeks," he said. "I had organised this trip to Saudi Arabia having cancelled it previously.
This time I couldn't cancel it. I am sorry for what I did and I wait to see what the club decides to do." The affair has made it increasingly unlikely that Messi will remain at PSG beyond this season, when his two-year contract with the club expires.