But Liverpool must make sure that Virgil errors don’t become a habit for defender
Last season, Liverpool went to Napoli and lost a Champions League group game before going on to win the title, so there's no need to press the panic button after they lost there again on Tuesday night.
It's interesting that the midweek games were the opposite of last weekend's Premier League fixtures. Liverpool followed up a good domestic result with defeat in Europe, while Manchester City suffered a poor defeat in the league but enjoyed a good away win in Europe.
Liverpool's focus this season is very much on the Premier League, and this is only one defeat in Europe - not even a shock loss. The defeat will hurt their pride a bit, but it's not too big a concern.
I think you'll see a reaction from Liverpool away to Chelsea on Sunday - a good match to come back to after losing in the Champions League.
Liverpool did find life difficult in Napoli on Tuesday and you need to give the opposition credit for that, even though some of Liverpool's problems, and Napoli's goals, came courtesy of Virgil van Dijk, which you don't expect as he's normally so reliable.
You are allowed to make a mistake ... the important thing is to make sure you don't do it again in the next match.
We've never really seen van Dijk make errors, and the manager must be wary not to let something creep into his game where one mistake becomes two and then three. As a defender, you can become so afraid of making a mistake that you stay away from the ball. I have seen it. Your confidence takes a knock after a mistake so you can tend to hide.
Van Dijk was very strong last season and he has to get back to that level - being a physical figure and a leader at the back, going for the ball and not holding back.
We know the levels he can reach, so I hope that the Napoli game was just a blip for him and we'll see the reliable old van Dijk against Chelsea on Sunday.
A striker can go on a run and score a lot of goals and a centre back can be on a run where the manager relies on him, no question. But any central defender, no matter how good he is, can start a bad run, where you make a mistake one week, two mistakes the next week, and it takes you time to get it out of your system.
So for him, it's a case of facing up to the error he made in Italy this week and making sure he doesn't do it again. Van Dijk is so important to Liverpool that they can't afford him to go hiding.
I wouldn't worry too much about Liverpool's loss in Napoli as it's a tough place to go and Napoli could win a few of their home games. Liverpool will recover from that.
Chelsea losing at home to Valencia is more serious for them. In fact, losing at home could be fatal for them in the Champions League as that probably shows where Chelsea are right now.
There is an elite level in Europe and Chelsea are not there yet. I don't see them as contenders for the Champions League, but they should still be doing better than losing at home.
They have suffered with the transfer embargo and they have gained a lot of praise for playing young players, but they are still trying to compete in the Premier League and Champions League and it seems already that they are off the pace in Europe's top competition.
Manchester City, Liverpool and Tottenham will have enough over the course of the group stages to progress, but it will be a struggle for Chelsea.
The Champions League will be quite open this season but I don't think anyone expects Olympiacos, Valencia or Napoli to go and win it, or even get near the final. Liverpool were caught cold a bit and it was a slow start from them, but I like the fact that City responded to a league defeat by winning in Europe.
City losing to Norwich was a surprise but, like Liverpool in Napoli, they have to accept they will lose some games this season.
Being beaten by Norwich so soon after they lost Aymeric Laporte underlines the weakness that City have in terms of the squad and they now look like a side who could be in trouble if they get injures in key areas.
I expect Pep Guardiola to put Fernandinho in against Watford tomorrow and try to shore things up as he's more stable than John Stones or Nicolás Otamendi.
Last season they had the likes of Kompany to step in but he's not there now. Stones makes errors but he's not as rash as Otamendi and I think Pep will bring someone like Kyle Walker into the central area.
The City manager has options there but his job now is to work on the training ground and figure out what works best for him.