John Stones' recent struggles show why Manchester City returned for Aymeric Laporte, fixing one of their few flaws

The Frenchman is looking to make good on a deal he reneged on 18 months ago and join City

Aymeric Laporte is likely to be a Manchester City player shortly (Getty 2017)

If there is any structural weakness left in this Manchester City squad, top of the Premier League, heading for the EFL Cup final, still in the Champions League and FA Cup, it is only at centre-back.

It might feel like nit-picking at this stage, when City have one of the best and most expensive squads in world football. But this is a club that leaves nothing to chance. Which is why, after a long pursuit of Jonny Evans, they have turned their attention to a better, younger, more expensive option: Aymeric Laporte of Athletic Bilbao. He has a £56million release clause but City are willing to pay it.

If City complete the Laporte deal this week it would end a transfer saga that has lasted for as long as Pep Guardiola has been in charge at the club. When Guardiola first arrived in 2016 he wanted to sign Laporte and a deal was close, before the France international turned them down and signed a new contract in Bilbao instead. That frustrated City, who did sign John Stones from Everton that window. And 18 months on Guardiola has returned for Laporte.

But why are City happy to spend so much money – far more than they bid for Alexis Sanchez this month – on a centre back? They have only conceded 18 goals in the Premier League this season, just two more than Chelsea and Manchester United. Their defence is demonstrably better than it was last season, thanks to the arrival of Ederson in goal.

There is a lingering problem for City, though, which is that they are short of centre-backs. They only have four senior options there, one of whom is hardly ever fit, another of whom they tried to sell in the summer. Vincent Kompany has only started nine games this season and in the last of those, at Newcastle United he only last 11 minutes before limping off. He was on the bench again last night, for City’s game at Bristol City, and did not get on. He still plays well when picked, but cannot be counted on.

The first-choice pair is Nicolas Otamendi and John Stones. Otamendi has been one of the most surprising improvers of the season, starting 30 games and adding a new level to his game with and without the ball.

Laporte will leave Athletic Club after eight years in Bilbao (Getty)

But Stones, who started the season brilliantly, picked up a hamstring injury in November, missing six weeks of football. During that time City had to bring Eliaquim Mangala back in from the cold, giving 10 starts to a man they tried to sell in the summer and who has never looked comfortable in Guardiola’s system.

Now Stones is back but in truth he is still getting up to speed. He gave away the penalty in the first leg of the EFL Cup semi-final, mistiming a tackle on Bobby Reid. He struggled when City lost 4-3 at Anfield, and was pushed off the ball by Roberto Firmino as Liverpool went 2-1 up. Then last night at Ashton Gate he looked like a player still searching for confidence, over-complicating in possession, skewing a clearance leading to Bristol City’s first goal.

If Stones improves and settles then City can push on with him and Otamendi for the second half of the season. But if he gets injured again, or worse, if Otamendi is suspended, then they will be in trouble. They need a centre-back who can come in and compete now in Guardiola’s own style of play, which takes some learning. Laporte has always been a ball-player, which is why Guardiola likes him so much, and is eligible for the Champions League too.

The second half of the season will not be easy, as City try to compete for four competitions at the same time. They go to Wembley for the EFL Cup final on Sunday 25 February, then play Arsenal at the Emirates on Thursday 1 March before hosting Chelsea at the Etihad Stadium. City are pursuing history, but the margins are very thin. They are on the brink of success but still one injury away from a crisis. Which is why they are ready to pay Laporte’s release clause this week.