It is all very well, him telling the world and his players that there are no easy games (as reported in the Daily Mail):
'But let's not fool ourselves into believing that we are now entering a phase against the lower teams that will present us with easy pickings.
'That would be a rubbish attitude and if we slip into that kind of attitude I can't think of an easier way to blunt our challenge, because there just aren't any easy games in this league of ours.
But it seemed to have very little effect tonight. Maybe he needs to take a long hard look in the mirror, because his tactics and team selection are starting to put United at risk.
Right now it is his world-class strike force that have got the Red Devils at the top of the Premier League. But they aren't going to stay there long if they play like they did in the second half especially.
And if they set up and play like this against Real Madrid, they will get murdered.
What is more worrying is that this was only Southampton manager Pochettino's second match, but he worked out how to play United off the park. If only they could have come up with an end product.
All the worrying signs that were there last season in Europe were present again. Sir Alex utterly failed to find a way to beat Barcelona in two Finals. Southampton's performance showed us again that he still can't find a solution to a passing, pressing team.
Even if United get past Real Madrid, they'll never beat Dortmund or Barcelona on this showing.
But half of the problem was that Sir Alex simply can't resist tinkering.
With most of his squad fit, he's found a winning formula with Vidic and Ferdinand or Evans at the back, Carrick and Cleverley in the middle and Rooney and van Persie up front.
So why on Earth change it?