Former Grade One Referee Steve Conroy has slammed Lithuanian man in the middle Donatas Rumšas for failing to flash the red card over a potential elbowing incident in Celtic's Champions League tie with Lazio.

The flashpoint occurred in the first half with the Roman side's full-back Elseid Hysaj clearly harming the Japanese midfielder with his arm. 

But both the referee and VAR failed to take action.

Sharing his expert insights with, Conroy stated, "The oversight of a clear red card offence, unfortunately, slipped past both the on-field and VAR teams.

"There is no mitigation for this instance."

Celtic took the lead in the match through Kyogo, with his first Champions League goal, but the Serie A giants equalised before half time through a Matias Vecino header.

And the decision not to take action proved crucial to the outcome of the game as Lazio scored a late winner via Pedro's header.