"The joint bid stinks," Southall wrote in his column for bookmakers Paddy Power. "The way David Moyes has gone about it stinks.
"The entire world knows Marouane Fellaini and Leighton Baines are worth a lot more than the £28m offered and Moyes is disrespecting Everton. It's really despicable behaviour towards Everton and disrespectful towards the fans."
Moyes moved to Old Trafford earlier this summer as Sir Alex Ferguson's replacement following 11 years at Goodison Park.