Per Mertesacker knows Arsenal cannot afford to fail to qualify for next season's UEFA Champions League.
The Gunners have made their worst start to a Premier League campaign and Sunday's win over Sunderland was only their third victory of the season.
Arsene Wenger's men consequently trail fourth-placed Newcastle by six points and summer signing Mertesacker is aware they need to make up ground.
they won't get there they need to spend