Two-time champions Argentina need to beat the Netherlands in Sao Paulo on Wednesday night to set up a showdown with Germany at the Maracana on Sunday night.
Messi, who missed much of his domestic season with Barcelona due to injury, carries his nation's hopes on his shoulders as they seek to win their first World Cup since 1986, and even though the forward has picked up Man of the Match awards in four of Argentina's five games this tournament, Sky Sports expert Jamie Redknapp believes Messi is not as good as he was five years ago.
He told Sky Bet's Ed Draper: "People are talking about this being a new Messi now, but is he better than he was? Give me the Messi of five years ago any day of the week.
"He was a lot more mobile, quicker; he still does incredible things...but a few years ago he just looked a better player to me".
The Saturday Night Football pundit, who picked Argentina to win the tournament, has lost confidence in their ability to pull through, but still feels they could just pinch the win against a Netherlands side under the carefully constructed guidance of Louis van Gaal.
"They're still struggling to find the right system, the right balance", added former England midfielder Redknapp.
"In midfield they haven't got the guile they normally have and there's no Di Maria as he's going to be missing - he's a huge loss, but Aguero might be fit which is a big bonus."
"I'd say it's also the worst Holland side they've had in many years; so if this team does win it will surprise an awful lot of people back home when you think back to all the great sides that they've had.
"It's got elements of it; you've got Robben and Van Persie up front, but there aren't many world beaters in that side; if you go through it player-for-player they're a pretty average side, but they seem to be together, they know what they're doing.
"I think van Gaal should take a lot of credit for the system that he plays 3-4-3, or 3-5-2 . He's adapted and played a four at the back and that's what I've really enjoyed about this side.
"I think that's something we really do badly in this country; we don't get the best out of what we've got, whereas van Gaal's certainly getting the best out of this Dutch side because, as I say, I don't necessarily think it's a top side."
JAMIE'S SHOUT: Holland 1-2 Argentina
"I'm going to go with an Argentina win, there's not a great deal of confidence I say this with I must say, but I'm going to go with an Argentina win 2-1.
"It's very exciting now because there's not a great deal to choose between the sides."
FIRST GOAL: Lionel Messi
"I'm going to go for Messi, who looks like the one player who's going to score. I mean, its between him and Higuain or Lavezzi really but I'm going to go for Messi."