McNair received a straight red card with nine minutes left but, while his studs were raised as he challenged Bacuna close to the edge of the area, he appeared to win the ball.

Middlesbrough claimed a much-needed victory thanks to first-half goals from Duncan Watmore and Ashley Fletcher – after Isaac Mbenza had given the visitors an early lead – but Warnock is hoping the win did not come at the cost of losing the influential McNair to suspension.

The Middlesbrough manager said: "When I look at the sending off, I can't believe it. I said to the referee when he came off, 'You didn't give it, did you?' And he said, 'No', the linesman gave it.

"The linesman's 30 yards away and he hasn't got an angle to be able to see what's going on. How can he give it? It's scandalous really.

"If the referee had given it, fair enough because he's there. But the linesman? He can't be giving it.

"We'll definitely appeal it tomorrow morning. Paddy is distraught. He said, 'Gaffer – there's no way it was a sending off'.

"He hasn't caught Bacuna at all. I thought he might have caught him because I couldn't see initially from where I was, but when you watch the video back, Bacuna is trying to flick the ball way, Paddy gets the ball, and he doesn't catch him at all."

Boro's victory ended a five-match winless run and lifted Warnock's side to within three points of the play-off positions.

He said: "It's a big win for us. It's nights like that I'm really proud to be a manager, when they're putting their bodies on the line.

"Apart from the first 10 minutes where they caught us a bit, I thought we dominated and should have been out of sight by half-time.

"We never make it easy do we though? I thought we were well in control of the second half until the sending off."

Huddersfield are just five points clear of the relegation zone and, while manager Carlos Corberan was satisfied with his side's reaction in the second half, he was disappointed with the way they allowed Middlesbrough to take control in the latter stages of the first.

Corberan said: "I think we started well, controlling the game and we scored the goal.

"They created problems for us after the goal and we didn't do enough in the first half. They won a lot of second balls and we didn't find a way to continue our dynamic.

"As a team, we should be better, but they took control in the last minutes of the first half. We should have avoided both of the goals.

"We have conceded too many penalties and that's something we have to avoid.

"But in the second half we got more of the reaction I was looking for. We created enough chances to have got something out of the game as a minimum but unfortunately, we did not take them."