Messi, who is hoping to lead Barca to a famous comeback against Paris Saint-Germain in the second leg of their Champions League last-16 tie, is nothing like the player he was at his peak in the eyes of Domenech.
The Argentina international and his team-mates face a massive task on Wednesday, with PSG 4-0 up ahead of the return match at Camp Nou.
And Domenech, an ex-PSG player, feels the job is beyond Messi's men, particularly with Barca's talisman now apparently a fading force.
"It is a collective sport and one player is not capable of winning a match on his own," Domenech wrote in L'Equipe.
"The image that remains from the first leg is Presnel Kimpembe getting the better of Messi through power.
"How can you think that he will have a magic wand in the second leg? They must find a miraculous solution.
"Embroiled in problems about extending his contract, Messi does not have the energy he had when he was 20 years old.
"It is not easy to see that gradually he is losing his gifts. He insists on taking free-kicks even though Neymar takes them better, all so that he can continue to be the demigod he has been.
"He is more calculated now. He has lost that spontaneity and strength in his dribbling."
Domenech also criticised Barca as a whole, claiming they are far from the side that once ruled Europe, having paid the price for not adequately replacing the likes of Xavi and Dani Alves.
"They are a shadow of the team that dominated Europe," Domenech, who coached France between 2004 and 2010, added.
"The strong point of the Catalans has been a fantastic trio in midfield, Andres Iniesta, Sergio Busquets, Xaxi and later Ivan Rakitic.
"Iniesta is a shadow of what he has been, Busquets has suffered with the tactical changes and Xavi has not been truly replaced, neither has Alves.
"They have weaknesses in defence and in midfield. Barca frequently have problems when their opponents attacks and when they have to battle to win the ball back."