Liverpool's James Milner sent off by his former teacher, now referee, Jon Moss

Little did we know when referee Jon Moss issued James Milner with a red card during Liverpool's win over Crystal Palace that the pair had a history that extended far back beyond their Premier League days.

It came to light after the incident that Moss and Milner have known each other for a long, long time as the former was actually the latter's PE teacher at junior school.

Sure enough, a photo soon emerged on social media showing Moss (left) in his role as coach of the Westbrook Lane Primary School football team with Milner (centre, holding ball) as his captain.

Milner was given his marching orders in the 89th minute of the match and didn't even stop to look back as Moss produced the auxiliary right-back's second yellow card of the afternoon.

Who knows, perhaps it was a grievance 20 years in the making? Perhaps Mr Moss used to force his class to run cross-country circuits in the depths of winter while they all wanted to play football instead. We may never know.