Leeds would have been left back in control of their own fate had Gerrard's side beaten United's relegation rivals Burnley at Villa Park on Thursday evening but the Clarets left with a 1-1 draw.
Ashley Barnes fired the visitors in front through a penalty just before the break before Emi Buendia equalised three minutes after the break.
Gerrard, though, was left fuming after Burnley goal scorer Barnes escaped any punishment when elbowing Tyrone Mings in the face with just four minutes on the clock.
Referee Paul Tierney did not even award a foul and while the incident was checked by VAR, the challenge was viewed as reckless but not violent and Barnes walked away scot free.
"I think we should have been playing against 10 men from a very early stage of this game," said Gerrard, as quoted by Birmingham Mail.
"It was a clear red card and probably one of the clearest I've seen this season.
"That decision went against us and we made an individual error to make the task and challenge more complicated for ourselves.
"Apparently, the PGMOL said that there wasn't enough force for that to be a red card.
"Now, I heard it and I was 60 yards away. He ran into the incident from 10 yards, he pulled his elbow back and he smashed him in the face.
"I mean, have you got to break someone's cheek or have you got to make someone go off for it to be a red card? Everyone knows it's a red card. It's a fact.
"There's four officials outside with VAR. We've also got a group now, outside of that, who all think that wasn't a red card.
"Now, I have to disagree with them all. For me, it was a clear red card. Ashley Barnes got away with one for sure, it's as simple as that.
"Does anyone disagree with that in the room? Does anyone disagree with that, no?"
The result left Villa in 14th place and Leeds needing a better result than Burnley on the final day to avoid going down.
The third-bottom Whites and fourth-bottom Clarets are level on points but Leeds have a minus 20 worse goal difference.
United visit Brentford on Sunday whilst Burnley are at home to Newcastle United.
Reflecting on his side's performance against the Clarets, Gerrard told avfc.co.uk: “It was a similar pattern to quite a few games this season where we’re getting in good areas, we’re asking some good questions and managed to score a fantastic goal, but it’s not enough, especially if you’re making individual errors and give a penalty away.
“In these situations, moving forward, we need to be better and show more quality.
“I’m pleased with a lot of our play, we got into some good areas and their ‘keeper’s been on top form tonight.
“I thought we did enough to win the game but I’m disappointed to let two points go again.
“We threw everything we had at it. We had 16,17 efforts tonight and we’ve managed to score one goal, so that’s on us to improve.”