Marshawn Lynch's mother tells TMZ Sports ... she believes her son still has gas left in the tank and will NOT retire ... not yet at least.
We asked Delisa Lynch about the comments Seahawks G.M. John Schneider said about her son -- that he was under the impression Lynch would retire before next season.
But Delisa -- aka Momma Lynch -- says, "I really believe we haven't seen the last of Beast Mode!!!"
She added, "My younger son [Davonte] will be coming out next year. I told [Marshawn] to wait for his brother."
FYI -- Davonte is a running back at New Mexico Highlands University ... and Momma Lynch's goal is to have BOTH of her sons playing in the NFL at the same time!