BT Sport pundits Rio Ferdinand and Owen Hargreaves have highlighted why Man City have struggled defensively this season amid a rough run in the Premier League.
City were held to a 1-1 draw against West Ham at the weekend and have only picked up eight points from a possible 15 in the top tier this season.
The Blues began the Champions League tie at Marseille in the right fashion this evening with an opening goal from Ferran Torres, but pundits and former United players Ferdinand and Hargreaves believe there are issues at hand defensively for Pep Guardiola.
Asked by presenter Gary Lineker if they have got it right after transfer spending on defenders such as Ruben Dias and Nathan Ake this summer, Hargreaves told BT Sport: "I think Dias and (Aymeric) Laporte is right (in the centre-back roles). Kyle (Walker) has been one of their best players this season but I think the left-back is still an issue.
"But in terms of partnerships with Dias and Laporte, I think they are going to get there with time."
Ferdinand added: "It's huge (the gulf since Vincent Kompany left). We have seen it down the years. When clubs don't reinforce in a particular area when they are losing big players, it's a huge area of importance.
"It's not just about the one player, it's about the relationship you create. The whole team feeds off of that and if you have got that foundation in a team that is secure, it's a comfort for everyone else. They struggled with that last season and hopefully they can rectify that this season."
