You have to worry about Manchester United when their best player in their last two games has been goalkeeper David de Gea.
He has made big saves against Villarreal and Everton and the Spaniard is not getting the credit he deserves for it because of the phenomenon at the other end of the pitch.
I’ll come back to Cristiano Ronaldo in a minute, but first I have to look back on another 90 minutes of disappointment at Old Trafford against Everton, where United were a curate’s egg.
We had good defending and great blocks from Raphael Varane and Victor Lindelof, as well as de Gea’s saves, but despite all that Everton ran through United almost at will at times.
It was lovely to watch if you are a Toffees fan, and it all contributed to a match that was very easy on the eye and certainly made my lunchtime pass quickly.
But I was just thinking about how any decent Serie A team, with their almost sacred focus on defending, would have dealt with United yesterday.
Juventus, or Roma or the Milan clubs, would have coped comfortably with United’s attack and then they would have sliced through for goals on the break.
Italy’s stars of their Euro win, Chiesa, Immobile and Varella, would have torn United to ribbons given the space and latitude afforded by United to Everton in this one.
Letting the gap grow at the top of the table is something Ole Gunnar Solskjaer dare not do.
And it doesn’t matter if it is Liverpool or Chelsea or City who forge the gap.
A gap means a United team and squad, that is always vulnerable to a result like they got against Everton, just is not going to win the Premier League.
You just know their three other main rivals are not going to drop many points, unless it has to happen because they are playing against each other.
When next weekend’s international break is over, United’s next four games in the Premier League are away to Leicester City and Spurs, and at home to Liverpool and Manchester City.
With a brace of vital Champions’ League ties against Atalanta of Italy sandwiched in between them.
At the end of that run of games, United’s Premier League and Champions League dreams could be in tatters.
And God only knows where that would lead – I suspect the three-year contract in Ole’s back pocket would not be worth the paper it is written on.
It could happen too, for right now, I’m struggling to see United beating either Liverpool or their noisy neighbours, even at Old Trafford.
Europe could be a different thing. That win last week over Villarreal was a huge result, because United now have a great chance of getting into the last 16.
And from there winning the Champions League is only seven matches away, all one-off games, with no away goals anymore, that would all have different dynamics.
Yes, you would fret about Manchester United’s defence running into the star-studded attacks of PSG and Bayern Munich right now.
But the opposition would worry too about United’s magic man, Cristiano Ronaldo.
I’ve come back to him now, so it’s time to make my point about the Portuguese superstar being a sub against Everton.
Yes, Ole could have started him, after all he is now heading off for international duty with Portugal.
He won’t be playing again for United until Saturday week.
But you simply have to manage the man’s workload cleverly.
He’s 36, not 26, - a very fit 36, yes - and Cristiano has always looked after his fitness very well.
But he still cannot go for 90 minutes in every game, not in English football, not if you want him to deliver in European action too.
Did you notice how against Everton, a couple of times, after he came on, that Ronaldo was looking for fouls that the referee simply waved away?
English football is more physical than Spanish football, and it is not as cynical as Italian football.
But Ronaldo had to know that as soon as he showed an interest in joining any Premier League club that he was opening himself up to any number of defenders who would have no problem barging into him – and worse!
It is brilliant for United to have Ronaldo back, but it is not all going to be plain sailing.