Matthew Stafford's wife is admitting she made a mistake by going public with the quarterback's communication struggles in the locker room ... calling it, "probably the worst thing I've done when it comes to him."
Kelly made headlines after revealing the 35-year-old Rams star wasn't connecting with his younger teammates on her "Morning After" podcast last week ... when she said the Super Bowl champ has found difficulty vibing with guys compared to years past.
Now, Kelly is regretting her decision to share that info ... telling Local 4 in Detroit, "That was tough.