Lionel Messi high-fives Manchester City youngsters (photo: Manchester City)

Lionel Messi delighted children at Manchester City's Academy when he made a surprise visit to a training session on Thursday.

The five-time world player of the year has been based at the club's training complex this week as he and his Argentina team-mates prepare for a friendly against Italy at the Etihad Stadium on Friday.

Messi's appearance stunned Man City youngsters (photo: Manchester City)

Accompanied by City favourite Sergio Aguero, who has since been ruled out of Friday's game through injury, Messi made the day for some of the club's U7 and U8 sides as he took time out to watch the children.

Both Messi and Aguero were happy to pose for photographs with the youngsters, which were later published on the club's Academy Twitter feed.

Messi offers academy youngsters some word of encouragement while Aguero watches on (photo: Manchester City)