David De Gea has come in for some criticism for his role in Tottenham's equaliser against Manchester United, and I have to say I agree with my ex-team-mate Gary Neville - he was at fault for the goal.
Although he had a decent game and produced some quality saves, he cost his team two points with a weak punch clear.
Dealing with crosses is a major part of the British game, and he just doesn't do it effectively.
You don't always have to catch the ball, but if you punch you have to do it decisively and get some distance on the ball.
It's not the first time - he could easily have cost them against Newcastle, and his lack of certainty seems to have spread to the back four.
At some point, probably the end of the season, Sir Alex will have to make a decision over whether he can persist with De Gea.
Nearly every title-winning team has a great goalkeeper. Peter Schmeichel, Tim Flowers, David Seaman, Petr Cech, Edwin van der Sar, Joe Hart - if United manage to stay on top it will definitely be the exception.
De Gea just doesn't seem too happy. He is a lad whom misses home, his girlfriend is still in Spain and he's struggling with the language a bit. The pressure of being Manchester United goalkeeper is a lot for a young man to bear.
I think there's always a risk with Latin goalkeepers. Not too many of them have been successful in the Premier League. Liverpool fell on their feet with Pepe Reina, but he doesn't play like a typical Spanish keeper. He is strong, physical and catches the ball.
It took a long time to replace Big Pete and United eventually did it with Van der Sar, a hugely experienced player with the strength to cope with the pressure.
That being so, it was a little surprising that they went for such a young player.
There's no doubt he has some talent, but he's the sort of player you'd rather have when he is 30 and has made his mistakes elsewhere.
I like what Chelsea are doing with Thibaut Courtois - sending him out on loan to Atletico Madrid to gain experience. But it's too late for that with De Gea - loaning him out would seem like an admission of failure and I'm not sure we'd see him back again.
I'm not sure Sir Alex should be rotating him with Anders Lindegaard as he has done this season.
Goalkeeper is the one position where you need a clear number one. The chopping and changing creates uncertainty, and can affect the relationship between the keepers.
I don't really think Lindegaard is a viable option, either. He made two big mistakes in the 4-3 win against Reading.
However, that game had an incident which demonstrated it is not just the goalkeepers to blame.
At corners, most teams put a man on the goalkeeper, and the defending team use another player to mark him.
You need to put that defender on the far side of the attacker - further away from goal - that way, if there's a collision between the goalkeeper and the attacker you will probably get a free-kick.
However, for United Patrice Evra insists on putting himself between the goalkeeper and the attacker. Getting goalside is usually the right thing to do, but not in this case - if there is a collision, it is between the keeper and his defender so you cannot win a foul.
Although the goalkeeper situation is a major reason for United's problems at the back, it is not the only one. Somehow they have managed to survive this season, but if they don't sort things out it could cost them the title.