The Argentine says that the Brazil international goes to ground too easily, but he had nothing but praise for Diego Ribas after the midfielder's stunning strike at Camp Nou
The Brazil forward netted the equaliser for the Blaugrana, calmly converting Andres Iniesta's stunning through-ball to leave the all-Spanish quarter-final clash beautifully poised ahead of next week's second leg at the Vicente Calderon.
However, while Simeone does not doubt Neymar's talent, he believes that forward is guilty of repeatedly going to ground too easily.
"Diving is his characteristic, like Alexis Sanchez did when I coached him at River Plate," he told Sky Sport. "This part of his game lets him down."
Diego Ribas had put the visitors ahead against the run of play with a thunderous effort from the edge of the box and Simeone praised the substitute before heralding the efforts of all his team in the first leg.
"Diego Ribas played a great game and I'm glad for his goal," Simeone told reporters regarding the player who replaced the injured Diego Costa a third of the way into the match. "He needed that and the team needed him.
"You see that me saying Costa was injured was not a ploy; we've had some problems with him.
"We'll see what they say after the tests to see how long we have to be without him. We will use Raul Garcia, Villa and Adrian in the meantime.
"The team did a tremendous job in a match where both teams have competed with different styles. Everyone did what was best for the club.
"I like to face Barca because we learn and improve. I'm happy with the efforts of the players and the result is good, but everything is open still. The return leg will be a very tough and exciting game."
Atletico, whose players picked up six yellow cards at Camp Nou, host Gerardo Martino's men next Wednesday.