David Moyes did not hide his disappointment at the decision not to show James Tarkowski a red card during West Ham's 1-0 defeat by Burnley.
Clarets skipper Tarkowski was lucky to stay on the pitch early in the second half after planting his studs into the thigh of Jarrod Bowen.
It was a similarly ugly challenge to the one which saw Arsenal striker Eddie Nketiah sent off 24 hours earlier, but referee Michael Oliver showed only a yellow card and VAR chose not to intervene.
Hammers boss Moyes said: "It was only brought to my attention afterwards but, look, it's a red card.
"It's not going to change the result but it's really disappointing the referee didn't see it as a red, the linesman didn't, and we've got the chance to go to VAR to make a decision on it.
"For me it's gone, but it's right that it's brought up and asked why it's not been given.
"We've questioned a few of the decisions against us and had responses back that we don't agree with, so I'm guessing I won't agree with the response this time either.
"I'm still hoping in the games we've got left that something will go our way."
Burnley boss Sean Dyche said that he did not see the incident.
"I presume that's what VAR is there for. I can't remember if their players reacted," he said.
West Ham missed the chance to climb further away from relegation trouble after Jay Rodriguez fired Burnley to victory with a bullet header that went in off the underside of the crossbar.
They had chances to equalise but Michail Antonio, Tomas Soucek and record signing Sebastien Haller failed to convert them.
"I'm disappointed we didn't take something from the game but you have to give Burnley credit for the way they defended," added Moyes.
"But we missed two or three outstanding chances. You don't normally get that number of opportunities to win matches in the Premier League."