UEFA referees' chief Pierluigi Collina has claimed that the tackle which broke Manchester United left-back Luke Shaw's leg should have been punished.

Referee Nicola Rizzoli took no action over the challenge by PSV Eindhoven's Hector Moreno on the 20-year-old defender last month.

Once play got back under way, Moreno went on to score as the Dutch side came from behind to beat the Red Devils 2-1 in their Champions League Group B encounter.

Collina told BBC Sport: "We certainly reminded our referees to be very, very careful with this matter. Nobody reacted because what was perceived, even by players on the field of play, was the ball was played.

"We need to make people aware that if you want to protect the safety of the player, even challenges on the ball but risky in terms of endangering safety of an opponent can be punished, should be punished."

Shaw is expected to miss out on the remainder of the season following his injury.