Southampton legend Lawrie McMenemy was shocked by the sacking of Nigel Adkins.
Some fans are threatening a boycott after chairman Nicola Cortese axed the man who led Saints to back-to-back promotions, replacing him with Argie Mauricio Pochettino.
McMenemy, who masterminded Saints' 1976 FA Cup triumph, said: "With due respect to the man, what does he know about our game? What does he know about our Premier League?
"He hasn't got that long to get things sorted out.
"The games come thick and fast. Everton at home on Monday isn't easy - then it's a trip to Old Trafford."