The former Anfield hero has dismissed suggestions that the likes of Jose Mourinho or Pep Guardiola could be heading to Merseyside to replace Kenny Dalglish
The Merseyside outfit are searching for a new boss following the dismissal of Kenny Dalglish, who guided the club to League Cup success but a disappointing eighth-placed finish in the Premier League.
And McManaman dismissed suggestions that the likes of Jose Mourinho and Pep Guardiola could be heading to Anfield as fans not "living in the real world”.
He told reporters: "You [Liverpool] can't identify Pep Guardiola and go and get him, you can't identify Jose Mourinho and go and get him.
"Those days of that type of appointment have long gone. It's unrealistic, isn't it? Of course, we'd like Pep or we'd like Jose Mourinho - but we're living in the real world.
"I don't know who's available, who's willing to come. The finance is a big thing, whether you're going to have to extricate someone from a contract.
"It's not like it was 20 years ago."
Wigan have given boss Roberto Martinez permission to speak to Liverpool over the vacancy this week, but McManaman admitted he does not know if the Spaniard is the frontrunner.
"I know they're speaking to a number of managers, aren't they, and trying to bring in the right appointment," he continued.
"People are picking on Roberto Martinez and [Swansea boss] Brendan Rodgers.
"They're both wonderful managers and Roberto Martinez is a superstar - he's a friend of mine."