Martin Keown has warned former club Arsenal that their Premier League title hopes hinge on whether or not they beat stuttering Chelsea at Stamford Bridge on Saturday.
Defeat for the Gunners could see them fall eight points behind high-flying Manchester City - who host West Ham United at Eastlands later in the day - after six games.
Arsene Wenger's side went down 2-1 at Dinamo Zagreb in Champions League action on Wednesday, while the Blues - who have lost three of their first five league outings - bounced back by beating Maccabi Tel Aviv 4-0 in West London.
"Both teams' confidence is brittle going into this," Keown told the Daily Mail. "Chelsea will feel that they are bouncing back - suddenly this has become a different game for Arsenal.
"It's then how they apply themselves. They got a drubbing in early kickoffs at Anfield and Chelsea, and there can't be any hangover even though they'll come back late from Zagreb.
"Jose Mourinho's team will start like a house on fire. Victory rescues their season. "Arsenal don't want Mourinho talking afterwards about how special he is again and how Arsenal have failed again. Wenger needs to create that urgency that their season hinges on this match."
Wenger has already edged out Mourinho this season, after Arsenal pipped their London rivals to the Community Shield in August.