It had been a great start to the season at Anfield but worrying signs in the Merseyside derby were confirmed at the KC Stadium.
Liverpool are clearly very vulnerable defensively when the opposition plays in a certain way: they seem to struggle with more physical centre-forwards plus they just can't seem to defend crosses.
We've also learned that the squad isn't sufficiently deep. Brendan Rodgers just does not have enough good players at the club.
Without the big three of Suarez, Sturridge and Coutinho playing and performing, things don’t look the same. Those three offer hope going forward but beyond that there isn't much else.
Sturridge could miss up to 10 Premier League games and his absence will of course be a massive blow.
In football you always expect to lose players in games to injury but Rodgers must be so annoyed that he has lost Sturridge for such a long time during a quiet week of training – you just don't expect that.
You do build a squad to deal with injuries though. Liverpool signed eight new players in the summer – but the problem is that most of them haven't found their best form or are simply not good enough.
They were desperate to get Aly Cissokho and Victor Moses in on loan but Cissokho was on the bench on Sunday and Moses has struggled to keep a regular place in the team.
Liverpool did great business last January getting in Coutinho and Sturridge but the deals they did this summer make you worry about the recruitment process, and whether last year they just got lucky. When you are going to carry a smaller squad than some of the top teams you have to make sure that nearly every signing counts.
It is not all doom and gloom for Liverpool as their upcoming home games during this tricky period should keep them in touch.
The next five home games are against Norwich, West Ham, Cardiff, a rematch with Hull and Aston Villa, and even without Sturridge you would be disappointed if they did not get 15 points from 15.
Anfield has been very kind to Liverpool this season. They are scoring plenty of goals with not many going in the other end but away from home they have been leaking lots of goals and with games at Tottenham, Manchester City and Chelsea coming up you would have to worry they would go away from those games empty handed given the way they are playing at the moment.
Staying in touch is vitally important though. If they drop off the pace they risk Suarez being unhappy again and they are particularly vulnerable to bids for him in January as he is one of the few top strikers in Europe who is still eligible to play in the Champions League.
It is also important to stay near the top four because Rodgers has said he wants to bring in two players in January who can go straight into the first team, but what are the prospects of getting a top player if it looks like Liverpool won't be in the Champions League yet again next season? That's where top players want to play.
And finding the right players for Liverpool is the big test facing everyone at the club in January. You can name lots of players who would greatly improve the team but how many of them are realistic signings?
Where do Liverpool start too? They have plenty of centre-halves but you would worry about the quality of play at that position in recent games. Left-back is a concern with young Jon Flanagan being asked to play there out of position. The midfield has been overrun in away games so you would like to improve that area, and of course the Strurridge injury has raised the question about whether there is enough strength up front.
Top four has to remain the aim but it looks like they might be fighting for just the one spot. It is hard to pick flaws with Arsenal at the moment. Whether they win the league remains to be seen but a top-four spot looks assured, and you just need to look at the type of players that Chelsea and Manchester City can bring off the bench to see how strong their squads are.
So Liverpool are competing with Manchester United, Tottenham and even Everton for that final spot. The owners and the players seem 100 per cent behind Rodgers but questions will be raised if Liverpool are on the outside looking in again come the summer.
The recruitment issue will again be raised and it will be even more difficult to hang onto Suarez because a player that good deserves not only to be playing in the Champions League, but playing for a team that has a realistic chance to win it.
At the moment Liverpool look a long way from being that type of club.