Although former Red's captain Barnes believes that Salah would struggle to perform at the same level for Los Blancos as their team would not be set up to maximise his strenghts in the way that Jurgen Klopp's Liverpool side are.
"When we lost here 5-0 at the beginning of the season, everybody saw the quality of City even when we were one man down, the preparation for the season, signings, the best coach in the world".
"You can not push a player through a game".
He is just four goals away from a career-best season tally and says he wants to keep improving year on year.
"That is how it is with all of them, if they are not 100 per cent fit they can not be involved".
Aguero is fit enough for a spot on the bench after receiving a tough challenge from Ashley Young in the Manchester derby on Saturday. But it appears Klopp is ready to finally give him a run-out from the off.
And with Dutch centre-back Virgil Van Dijk also in their ranks, the team is starting to look the strongest it has been in years.
"The only way to work in this job is to be focused on the next game and that is Everton".
"I always think about how we can win the next game and we need fresh legs for that".
Allardyce is hoping to exploit that, saying: "I think it's an advantage we could possibly take".
The Liverpool Echo reports that the two players are in-line to feature at the Etihad, but Alberto Moreno is a doubt for the game.