Sadio Mane's goal was wrongly ruled out in the game against Arsenal

In the first half, Sadio Mane has scored a goal which was disallowed as a result of an offside. The ball came to Mane from James Milner to Firmino then to him. Although Mane was offside from the original Milner pass, he was onside in the second phase from Firmino's shot. Though there was plenty of confusion, the flag went up and Liverpool were denied their opener, writes SkySports.