The former Anfield star thinks his old club are as many as five players short of mounting a title tilt.
Heskey has identified Borussia Dortmund striker Aubameyang as the player Jurgen Klopp should line up – alongside other top stars to transform the spine of his squad.
Heskey said: “Liverpool would need to do a lot in the transfer market win the Premier League. It will take a sustained effort in numerous transfer windows to make the necessary signings – it’s not a quick fix.
“I think Liverpool would need to sign four or five players, with the priority being to improve the defence and the goalkeeper.
“The club would also need to sign a defensive midfielder, I still don’t think they’ve replaced Dietmar Hamann and he left over a decade ago. Lucas played there for a while and did well, but it has been a struggle and I don’t think they’ve got it right.
“In terms of strikers, Liverpool should sign Pierre-Emerick Aubamayang. That signing would make a real statement to both the fans and the rest of the Premier League that we mean business.
“Liverpool need to sign an out and out striker who will play regularly and who we can depend on to score those decisive goals.
“I thought Daniel Sturridge could have been that, but he struggles with injuries and Klopp doesn’t pick him even when he’s fit.
“Roberto Firmino can play up front but he’s not an out and out striker and we can’t expect him to fire us to the title.”
Liverpool have got off to a shaky start to their Premier League campaign and Heskey is worried about the side’s consistency.
He told sportingbet.com: “Inconsistency will be any team’s downfall.
“Liverpool are already seven points adrift and are at risk of losing further ground because the other top teams are winning games even when they’re not playing particularly well.
“We can’t afford to fall further behind even at this stage of the season because the top teams very rarely drop points.”
