This article is part of Football FanCast’s In Numbers series, which takes a statistical look at performances, season-long form and reported transfer targets...

Manchester City's defence was at sixes and sevens too often against Liverpool, as the champions slumped to their third to defeat of the Premier League season. Two quickfire goals early on in the game and a Sadio Mane header in the second half showed there any still many gaps within the City backline.

The likes of Ederson were clearly missed, whilst the absence of Aymeric Laporte and departure of Vincent Kompany have equally been felt during the season. At right-back, Pep Guardiola has been experimenting and perhaps still does not know his best player in that spot, having played Joao Cancelo five times in the Premier League, as well as Kyle Walker.

Cancelo signed for City this summer for £27.5m and hasn't managed to dethrone Walker just yet, though he has shown enough promise to suggest he can eventually become the club's first-choice right-back.

Just a week before the battle on Merseyside, Walker put in a game-winning display against Southampton by assisting the equaliser and scoring the winner. However, his form over the past year has seen him miss out on the England squad, raising questions marks over the true extent of his ability in the process.

The 25-year-old right-back has so far averaged 2.4 tackles per game in the Premier League and two tackles per match in the Champions League. On the other hand, against Liverpool, Walker made just one tackle and was beaten twice in the game.

In truth, throughout the tie, Mane had a fairly easy game against the former Tottenham Hotspur man.

Even going forward the 29-year-old made just 34 passes, which equalled to a 74% completion rate, whilst Walker also failed to accurately complete a single cross.

Despite his proven ability going forward, Walker's defensive frailties have been exposed at times.

With Cancelo still relatively new to the club and looking to stamp his mark at the Etihad, Walker's latest performance will certainly give Guardiola food for thought moving forward.