Ronald Koeman believes English football should allow the fourth official to have a greater input into refereeing decisions after seeing a clear penalty turned down in the defeat against Liverpool.

Referee Kevin Friend was in the centre of the action in the first half at St Mary’s as he turned down two penalty appeals from Filip Djuricic either side of Philippe Coutinho’s opening goal.

He later also refused to give a borderline handball outside the area by keeper Simon Mignolet and waved away another appeal for a spot kick for handball by former Saints defender Dejan Lovren.

Koeman had sympathy with all those decisions, other than the second Djuricic appeal, which looked like a major error from Friend.

Koeman said: “The first situation is difficult because if you whistle it’s a penalty and a red card and you have to be sure as a referee to do that.

“Maybe Djuricic in that moment maybe a little bit too easy falling down in the box but about the second there’s no question.

“I don’t understand the referee if that happened and that happened the first time.

“Human people can do mistakes.”

Koeman believes involving the fourth official more could help eliminate such errors in the future.

“I think in every country it’s always critics to referees,” he reflected.

“I don’t do that. It’s a difficult job what they have to do.

“I think the fourth referee can do much more than he does in England in the Premier League.

“He’s watching the game like the people on the touchline, he can help much more the referee about decisions and technology is a big help for referees in a difficult situation, not like penalties, but finally it’s in balance maybe a little bit more unlucky in that.”

Of the possible Lovren handball he added: “I don’t know, I have to watch back that kind of moments in the game but it’s always difficult if handball is a penalty yes or no.

“Everybody had that discussion about yes or no penalty but it’s about the decisions of the referees.

“You can have a discussion about that but not about the second situation because it’s so clear about the penalty.”

Koeman admitted it was a frustrated dressing room at half time, but was philosophical enough.

“Of course, angry about 1-0 down in the game because we deserve much more in the first half,” he said.

“In football it’s all about scoring goals and Coutinho made a great goal and we didn’t score with more chances what we had than Liverpool in the first half but that’s football.”