London - Chelsea manager Antonio Conte and Arsenal boss Arsene Wenger have no margin for error as they fight to avoid being frozen out of the Premier League's top four and next season's Champions League.
When the London rivals clashed in the Community Shield in August, the sparkling sunshine at Wembley provided a fitting backdrop as they looked ambitiously towards the new season.
But just seven months later that optimism has given way to the harsh realities of winter and the realisation that both Conte and Wenger could be out of a job at the end of the season.
With fourth-placed Tottenham Hotspur at home to Huddersfield Town on Saturday, Chelsea - with three defeats in their past four league games - could be five points outside the top four by the time they kick off at Manchester City on Sunday.
Last weekend's defeat at Manchester United was another bitter blow and Conte knows returning to Manchester to face red-hot City is hardly the ideal fixture for Chelsea to get back on track.
Chelsea's players are reportedly unhappy with Conte's intense personality and ultra-demanding training sessions.
And, asked how damaging it would be for Chelsea to miss out on the Champions League, Conte's answer hinted at frustration with his players' efforts.
"I am repeating the same concept many times but in this league to find a place in Champions League is not simple," Conte said.
"There is this risk to stay out of the Champions League. This could be a possibility for sure.
"We must be ready to fight, to be concentrated and to understand that this target is an important target for us but it won't be easy."
Across London, Arsenal have fared so badly that Wenger's future appears more uncertain by the day, despite breaking the club's transfer record twice this season.
Arsenal's FA Cup final victory over Chelsea last May was followed by the announcement that Wenger had signed a new contract after months of debate over his future, sparking talk of a long-awaited renaissance at the Emirates Stadium.
However, Wenger once again finds himself vilified by Arsenal fans after the Gunners slumped to sixth place, crashed out of the FA Cup at Nottingham Forest and succumbed to a tame League Cup final loss against Manchester City on Sunday.
On Thursday, Arsenal suffered a second chastening 3-0 defeat to Pep Guardiola's league leaders in just five days and Wenger admitted confidence at the club was low.
Sunday's trip to Brighton will serve as another referendum on Wenger's belief that he remains the right man to revive the Gunners.
Arsenal have lost their past three away league games and are so far off the top-four pace that winning the Europa League may be their only chance of a return to the Champions League.
Despite the miserable results, Wenger is unsure if this is the most difficult spell of his 21-year reign as Arsenal boss and remains confident he can pull the club out of their tailspin.
"I live my situation with full intensity, I don't compare to any other situation I face before and that's part of my job," he said after Thursday's defeat to City in icy conditions.
"The reality in life is nothing is permanent," he added. "It is down to how you respond and what kind of focus and effort you show to turn things around."
Elsewhere, second-placed Manchester United are firmly in control of their top-four bid as they head to Crystal Palace, while third-placed Liverpool host Newcastle United.
Weekend English Premiership fixtures (all times SA):
Saturday, March 3
Burnley v Everton - 14:30
Leicester v Bournemouth - 17:00
Southampton v Stoke - 17:00
Swansea v West Ham - 17:00
Tottenham v Huddersfield - 17:00
Watford v West Brom - 17:00
Liverpool v Newcastle - 19:30
Sunday, March 4
Brighton v Arsenal - 15:30
Manchester City v Chelsea - 18:00
Monday, March 5
Crystal Palace v Manchester United - 22:00