Ronald Koeman was frustrated with referee Lee Mason after the official refused to give Saints what appeared to be a clear penalty.

Koeman’s side were a long way from top form against Stoke, but it seemed like they should have won a second half spot kick as Graziano Pelle was felled in the area.

Mason had a decent view of the incident but surprisingly waved away the Saints appeals, even though TV replays backed up the first impression that it should have been given.

Koeman said: “I don’t understand. From my distance to that situation it’s very clear.

“I don’t know why the referee from maybe five yards or something don’t whistle because it’s a clear penalty.”

There was a slight surprise in Koeman’s team selection as he left Sadio Mane on the bench.

The inform front man was the last back from international duty and returned from action with Senegal nursing a slight ankle injury.

In the end Koeman decided it was not worth risking him from the start and instead used him as a late sub, though there was no doubt Saints missed his pace and creativity.

“It’s always the question after international duty to make decisions about that,” responded Koeman.

“Sadio came back late Thursday in the morning, didn’t have the training session with the team, had an ankle problem, and that was the reason I didn’t start with Sadio.

“Normally without any problem, without any problem in freshness, he starts the game.

“That was the reason to change it, but it’s always difficult because the players are coming back.

“For the manager I think it’s the most difficult decisions to make, what are the best starting XI for the game because you are not really sure about the focus or the sharpness of the players for the game.”

The 1-0 defeat to Stoke brought to an end a fantastic run of form for Saints.

They had gone eight games unbeaten in all competitions before being downed by the Potters.

Koeman admitted that the run ending is a blow for his side, but had few complaints with the final result.

“It’s disappointing because you like to keep that because it gives everybody a good confidence, a good feeling, but we knew already to win against Stoke we have to be at our level and the Stoke team was more comfortable, more better, than Southampton.”