WWE Ringside Doctor -- Sues CM Punk for $1 Million ... Over Staph Infection Claims

Two former WWE superstars have been hit with a huge lawsuit from the WWE ringside doctor -- who claims the duo defamed him on a podcast ... when they trashed him over the way he treated a growth on CM Punk's back.

The man behind the lawsuit is Dr. Chris Amann -- who claims Punk and Colt Cabana defamed him on Colt's "Art of Wrestling" podcast back in November ... when Punk spoke out for the first time about his departure from WWE.

During the podcast, Punk repeatedly tore into Amann -- essentially saying he was a crappy doctor.

Amann says the two also claimed he misdiagnosed a growth on Punk's back -- a growth that Punk says later turned into a full blown staph infection.

But Amann says it's all BS -- claiming the statements are false and defamatory ... and now he wants the wrestlers to pony up more than $1 million in damages to his reputation ... plus punitive damages.

Colt and Punk had no comment about the lawsuit.