Ronald Koeman felt Saints were denied a clear penalty in the first half of their 1-0 defeat to Leicester City and that the hosts should also have been reduced to ten men.
With the score 0-0, Sadio Mané raced clear in the 32nd minute of the match, rounded Foxes keeper Kasper Schmeichel and struck a shot towards goal that was blocked by the arm of the back-tracking Danny Simpson.
Referee Michael Oliver did not give a spot kick, instead allowing play to go on, with Wes Morgan heading the decisive goal just six minutes later.
Koeman felt his side were hard done by, telling Southampton’s official YouTube channel: “First of all, I think we had a sloppy start in the game, we had problems.
“After ten, 15 minutes I think we controlled the game, we had good football, some good chances and one of the two, three key moments is a 'Yes' or 'No' for the penalty by Mané, and in my opinion it's a clear penalty.
"It's a very big moment, because then it's penalty and a red card and you're normally 1-0 up against ten players and then you win the game normally.
"What you need in life is to get good decisions and I know the job for a referee is difficult, because it's a big decision, but you're a referee if you take a good, right, big decision in the game.”
Koeman added: "After a difficult start, we grew in the game, we had some good, attacking football and, even after the 1-0 down, the second half we dominated, we had good football, we had good crosses, but it was not really good enough in our positions in the box and they defended very good by Morgan and [Robert] Huth, all the crosses.
“That's one of their qualities, to defend and keep a clean sheet, and we know, and then you have to bring a little bit more.”