Roy Keane laid into Fred after the Manchester United midfielder deflected Che Adams' shot into his own net.
Southampton opened the scoring at St Mary's when Adams ghosted into the United box before shooting at goal, with the ball hitting Fred's foot and squirming past David de Gea.
Keane insisted Fred should have done better, with the United man failing to close down the Saints forward to prevent the shot.
'Fred and Maguire have to do more when someone comes into your area,' Keane told Sky Sports.