Centre-Backs
Arsenal have had a centre-back crisis at the start of the season which forced Wenger to stick Nacho Monreal in the centre of a back-three in the 1-0 loss to Stoke City. Luckily for him, he can now call upon Laurent Koscielny to marshal the back-line again.
The French defender was suspended for the FA Cup final last season and the first two games of the season thanks to a red card in the final league game of the 2016/17 campaign.
His return will strengthen the Gunners rearguard and the captain's armband on a reliable player will be welcome sight for the Arsenal faithful.
Partnering him in defence will be Liverpool's reliable 26-year-old centre-back Joel Matip. The Cameroonian defender stands just a shade below 6'5" and has been Klopp's best defender in a while - with the player so happy with the game time that he declined to participate in the Africa Cup of Nations.
Matip is also capable of being a threat on set-pieces - a potent goal threat which makes him a valuable member of the squad.