Mark Hughes believes Simon Mignolet should have been dismissed for bringing down Mame Biram Diouf early in Stoke City's 3-0 home loss to Liverpool.
Mignolet was only shown a yellow card for tripping Diouf outside the area just as the attacker appeared set to restore parity in the 39th minute at bet365 Stadium.
Liverpool went on to add two further goals to Sadio Mane's opener through substitute Mohamed Salah, consigning the hosts to consecutive Premier League defeats.
Hughes, who also felt the ball had gone out of play in the lead-up to Mane's goal, felt aggrieved after the match.
"Mame Diouf nicked the ball past the goalkeeper, the keeper has wiped him out and should have been sent off. Clearly," Hughes said.
"Even if we had scored at the point and they had remained at 11 we still would have been back in the game. Obviously, that is a huge moment for us.
"The least we should have had was a clear run on goal. In my view, the keeper should have been sent off and they should have been down to 10 men.
"Given the way we were playing at the time, I think we would have gone on and made it really difficult for them."
The defeat leaves Stoke precariously placed in 16th, just three points clear of the drop zone ahead of Saturday's visit from fellow strugglers Swansea City.
"We have a big game at the weekend and we will need to face that with similar effort and determination," Hughes said.
"We have to make sure we get back to winning ways."