The Premier League’s refereeing body, PGMOL, has suspended assistant referee Constantine Hatzidakis after an incident during Liverpool’s match against Arsenal at Anfield.

During half-time, Robertson approached Hatzidakis to question a decision that went in favor of Arsenal, but ended up being elbowed in the throat by the linesman.

It is unclear whether the elbow was intentional or accidental, as images showed Robertson with his arm over Hatzidakis’ arm.

PGMOL has asked Hatzidakis to step down from refereeing duties until the investigation is complete, and the suspension is indefinite.

The outcome of the investigation will determine if further action is needed.