United failed to capitalise on a missed kick from Alex McCarthy three minutes in, and they were punished when Stuart Armstrong blasted across David de Gea's goal and into the net with Saints' first effort on target.
Immediately after the game, Mourinho cited United's lack of "mad dogs" as the reason for their second successive draw in the Premier League, but thought one player brought a particular bite to their performance.
Manchester United manager Jose Mourinho gave a furious dressing down of midfielder Paul Pogba in the locker room following the club's 2-2 draw with Southampton on Saturday, reports The Daily Record's Duncan Castles, calling the France worldwide "a virus".
Pogba, 25, returned to the team after being benched for the Red Devils' midweek Champions League victory over Young Boys. "Doesn't matter the system we play, has to do with the characteristics of the players".
Former Tottenham Hotspur midfielder Micky Hazard has warned Toby Alderweireld that he would be a fool to leave Spurs in favour of Manchester United due to the current situation at both clubs.
"We lost so many balls in midfield", Mourinho told BT Sport.
"What we did so well in the last 15, 20 minutes in the first half was to connect with the attacking players by transporting the ball, leaving the ball in the right moment, the right choice, pass, playing simple".
'In the second half we went back again to that dynamic where we lose too many balls midfield. The players they don't understand that simplicity is genius, especially in some parts of the pitch.
United now lie 16 points off Manchester City after just 14 games and it certainly looks like they'll face a real fight to even finish in the top four this year.
"There were examples of players fighting to the limits - Marcus Rashford, Phil Jones and many others - showing that respect for the shirt and for the club".
With Palace in better form than their league position suggests, it's understandable that they are priced at around 4/7 to win the game, but a 2-0 win for Palace at 13/2 makes plenty of appeal.