Garcia's comments come after Liverpool boss Jurgen Klopp said Salah was on his way to being compared with Messi following the Egyptian winger's fiery four-goal show in a Premier League outing against Watford on Saturday, March 19.
Notably, the 47-year-old Spanish tactician was in-charge of Osasuna when Messi's hat-trick helped Barcelona complete a 7-0 thrashing in the 2013/14 La Liga season.
Klopp had said Salah does not want to be compared with the five-time Ballon d'Or winner but maintained that his wrecker-in-chief "is in a fantastic way".
Salah became the first Egyptian footballer to score a hat-trick in the Premier League when he helped Liverpool crush Garcia's men 5-0 at Anfield and bury the disappointment of their defeat to league leaders Manchester City on March 10.
He opened the scoring as early as in the fourth minute of the game when he dribbled past Watford's Miguel Britos and slotted one into the bottom corner.
He doubled Liverpool's lead before the two teams went into the break. There was not stopping Salah in the second half as he added two more to his tally after firing in a cross, which was met by Roberto Firmino.
"For me, Salah is not the same as Messi – at the same level at this moment, yes, and you have the same shape to play against the similar formations of the two teams – but you don't prepare the same to play against both players, it is different," Garcia was quoted as saying by Liverpool Echo.
"They are different types of forwards, but both are equally dangerous. It is very difficult to play against them because they can both score in any moment," he added.
"They are both incredible players, they were both unstoppable, yes. Honestly, both are fantastic, and now Salah is in a very good moment, one of the best in Europe.
"That is the same with both, they have so many qualities, they can do it in a single moment. You can do everything right in your defence, and in one moment you are lost."
Salah sparkles in debut season with the Reds
Salah has been in a phenomenal form on his maiden season for Liverpool. The 25-year-old winger has scored 36 goals for the Reds in all competitions while finding the back of the net 28 times in the Premier League.
He is on top of the scoring charts in the 2017/18 league season, four clear of second-placed Harry Kane of Tottenham Hotspur.
Salah will be key to Liverpool's chances when they face tough Champions League quarter-final outings against City April 4 and 10. Notably, Pep Guardiola's men will be making a trip to the Anfield for the much-anticipated first-leg.