However, his appeals were turned down by referee
"I think even when Luis does get blatant penalties now he doesn't get them," said Gerrard.
"It is down to referees to not judge him and give what they see - if it's not a penalty don't give him one but if it's clear give it.
"He was booked at Sunderland but against United it was a penalty."
Johnson echoed the sentiments of his captain by adding: "Everyone has to do their job: they have to forget about who they are looking at and make their decisions and not let anything from the past affect their decision.
"They have to call the shots at the time, regardless of who it is."
Johnson found himself on the receiving end when he conceded the match-winning spot-kick at Anfield after
The England right-back was fuming as he claimed he did not touch the Ecuadorian, whom he accused of cheating.
"I've watched it 50 times - not that I needed to - because it wasn't a penalty, I didn't touch him, I have collided with
"Reputations go in front of people at times and because Valencia is not a known diver that is why he got the decision.
"I almost guarantee if it was exactly the same situation and it was Luis and not Valencia then it wouldn't be a penalty.
"It is cheating at the end of the day, that's what people call it.
"You can't describe [the feeling] but you don't expect people to do that - they are better than that.
"This is one the best leagues in the world and you've got someone doing that.
"I know it is difficult for the referee when we are sprinting as fast as we can but in the big games they are the differences and we expect the referees to make the right decisions.
"We are working as hard as we can to win the game and to have that taken away like that... I can't explain it.
"The referee said to me he had to give it so he obviously thought I had touched him. It is frustrating because I've not touched him."
"You see it in the modern game, across the board, a number of players go to ground too easily and they get their rewards sometimes," he said.
"If you look at Luis last week away at Sunderland he goes down, there is contact but he gets booked for it then yesterday he didn't get it.
"Every foul or maybe someone going to the floor isn't always a booking."
English Premier League