Arsenal legend Martin Keown believes Per Mertesacker 's omission from Arsenal 's starting line-up for Sunday 's win over Everton 'could be a defining moment in changing the club 's back four ' . January signing Gabriel Paulista was preferred to the German in defence , with Gunners boss Arsene Wenger telling BT Sport that the change was made in order to give Mertesacker a rest . Sportsmail 's Keown , speaking as a pundit on BT Sport , reacted to the news of Mertesacker 's absence for the crucial game at the Emirates saying : ' I do n't you can point the finger at one player after the Monaco game . It 's a big chance for Gabriel now , though . Martin Keown believes Per Mertesacker 's omission could be a defining moment in Arsenal 's defence . Keown ( third right ) was joined by Steve McManaman ( far right ) and Michael Owen ( second left ) on BT Sport . ' I think it could be a defining moment in changing Arsenal 's back four now , for sure . 'Mertesacker , with the experience he has in the game , should have been calling these young players back the other night , the two full-backs were just drifting up the pitch and not coming back . 'When he 's been left isolated one-on-one he struggles due to his lack of pace too . Gabriel is keen to defend so he 'll be relishing this opportunity to stamp a claim for a first-team spot . ' The German defender ( centre ) looks on despondently after Arsenal concede a third goal on Wednesday . Arsene Wenger has come under a barrage of criticism after Arsenal 's shock defeat to Monaco on Wednesday . Wenger , who has come under fierce criticism after Wednesday night 's 3-1 defeat by Monaco in the Champions League , maintained he is still fully committed to Arsenal , urging supporters to stand by the team ahead of the 2-0 win over Roberto Martinez 's men . In an interview with BT Sport he said : 'We have always been united at Arsenal so I ask the fans to stay behind the team and show how strong you believe in the team even after Wednesday 's disappointing result . ‘ In the last 25 years I ’ ve always finished in the top three four and that consistency has given me belief and confidence to continuing to manage at the highest level . I ’ m as committed as I ’ ve ever been to deliver success to this team . '
Arsenal beat Everton 2-0 in the Premier League on Sunday afternoon . Martin Keown was a headline omission from Arsenal 's starting line-up . The 30-year-old struggled during Wednesday 's 3-1 defeat at the hands of Monaco in the Champions League . Gunners boss Arsene Wenger said the German has been rested . Sportsmail 's Per Mertesacker believes it could be a defining moment in changing Arsenal 's back four .