The Stamford Bridge club have been linked with the goalkeeper over the past week.
When asked if the goalkeeper would be a good signing, the French defender was direct, admitting he wasn't sure the Argentina international would "be a good fit for Chelsea."
"I don't know if Emi Martinez would be a good fit for Chelsea," Gallas told Prime Casino.
"He’s a good goalkeeper. Obviously, he was a key player for Argentina. He’s done well at Aston Villa since he joined them from Arsenal those years ago, but I have to admit, I have some serious doubts about whether he would be a good fit for Chelsea.
"I don't know if he’s got the right profile to be the goalkeeper of Chelsea. When I think about his antics, I just don't think he would be a positive addition to the club.
"People talk about his personality, his passion, I’m not sure that is a good fit for the club. I don't think he would be the right goalkeeper.”
He continued: "Chelsea need a goalkeeper that is as good as him or maybe better, but with a different profile. Someone that does their job without doing all of the other stuff that Martinez does.
"I'm sorry but give me the name of one goalkeeper with the same profile. Name another goalkeeper who grabs his crotch and dances around when he makes a save, one goalkeeper who has done that who has played for a big club. You won’t be able to name one.
"Goalkeepers are crazy. Jens Lehmann, he was crazy. Carlo Cudicini, he was crazy. Cech was cool. Lehmann would never behave like Martinez – Martinez brings too much negative attention. You want a goalkeeper to make saves, keep clean sheets and leave the pitch. Martinez doesn’t do that."