Richard Dunne: 'Chronic back problem is crippling City'
If, as expected, Manchester City do end up losing their league title, they will really have lost it last summer in the transfer market when Pep Guardiola decided not to sign a centre-back.
You need to plan for injuries and suspensions and City didn't do that. They seemed to think they would be OK, but they didn't take into account that injury to Aymeric Laporte or the form of Nicolas Otamendi.
So they were wrong to not sign a defender in the summer. They did sign Rodri to give Fernandinho the chance to go and play in defence if he was needed, but they miss him in central midfield. More than anything else, that's their biggest problem.
Otamendi and John Stones have never been rock solid but when they had Fernandinho in front of them, he stopped a lot of the threats before they got through, and that Fernandinho-type player is not there as Rodri is not in the same vein, that's where they are losing the battle at the moment.
City either need to sign a centre-back or get Laporte back, because for every two good games they have they will then have a slip-up. They just have that hint of instability about them, which they didn't have last season, and other teams in the Premier League can sense it.
Attacking wise, they are fine, with Kevin De Bruyne and Bernardo Silva, but they just lack that defensive grit. It's surprising that Guardiola is so focused on details in so many other matters at the club and yet he didn't feel he needed a central defender in the summer.
Maybe he felt he could get away with it. In the past, he has been able to just fit players into positions if needed. Maybe he felt that a number of his players could fill in at centre-back. He did that with the likes of Javier Mascherano at Barcelona, just pushed them back into defence when necessary.
So he has done it before where it worked but the Premier League is another matter. There are different battles each week, different types of strikers, and it's not as simple as Guardiola felt it was.
For all their attacking prowess, and it is very good, City have failed over the last couple of years because you always think they're not strong enough at the back.
And now they need two centre-backs. One, Laporte, is out with an injury and the other two don't seem capable of putting together a string of performances to allow them keep clean sheets.
I can't see Guardiola going out to buy one, but they need someone who could come in right now and help out. Jonny Evans has been brilliant for Leicester, he knows the league and I wouldn't be surprised if they did earmark him to come in for a year or 18 months.
They will have to spend over £100million to get a top-class centre-back, someone like Evans could be good in the medium term but he is doing well at Leicester, they are happy with him and he's happy there, so the Foxes would be entitled to ask for a very big fee.
Toby Alderweireld is out of contract with Spurs at the end of the season, but would City really hand him a five-year deal?
The prices in the transfer market now are crazy. It's as if City are not buying a certain player but they are buying a position, and they are buying him as Manchester City so there is a premium price because of who they are.
So the options are limited but it's a risk to carry on as they are and not buy anyone in the hope that Laporte gets back, or that Fernandinho doesn't get injured.
When the season started, you'd have had City down as the one club who could cope with injuries and suspensions, but City now look like a side who could fall apart when they have one or two injuries.
Teams have already exposed City in the Premier League, as Manchester United did last week, and the big worry is seeing teams do that in the Champions League knockout phase.
You can't win the Champions League if you are not strong defensively and that's why City will face problems. There is a theory that City can focus on the Champions League now instead of the Premier League as they are so far behind Liverpool.
But that would be dangerous as well. As the Champions League progresses, by the time you get to March and the business end of it, some of the bug guns, like PSG, could possibly have their domestic leagues already sewn up so they can step back domestically and really go for it in Europe and they could make someone like City suffer.
I have always felt that City were a side capable of going on a run of 15 wins, but I might have to readjust that view with this current team.
They don't have that in them, they make too many defensive mistakes across the team and now seem to lack the potential to go on a run that could catch Liverpool.
The next month is crucial for Liverpool and if they come out of the Leicester game on St Stephen's Day, they will be really on their way. The focus for Liverpool is the Premier League, of course they want to retain the Champions League but if they need to rest a player for a Champions League game, they will do that.
Liverpool have that bit between their teeth now, every game is a grind but they do the job, go out and win. They've had back-to-back clean sheets and it's falling into place.
You can't say the same for Arsenal who seem to have made a mess of things. Again. You see how quickly Spurs moved when they wanted a new manager, Arsenal delayed and they don't have a succession plan, don't seem to have an idea of who they want and Freddie Ljungberg didn't get off to a good start.
They're in a bit of a mess, the team needs someone strong and stern at the top, they lack that, and that could work for City this weekend. Ljungberg seems to want to make people happy, but they need tough love and Ljungberg won't deliver that.