Chelsea occupy fourth spot with Arsenal the other side of the dotted line, and the Gunners know that defeat this weekend could spell the end of their Champions League hopes.
Arsenal fans could be forgiven for thinking that they have been transported back a year, with their team underperforming on the pitch and frustration growing at a lack of transfers.
Unai Emery's admission that the club can only afford loan signings this month was as perplexing as it was worrying, and while Denis Suarez and James Rodriguez have been linked with a move to the Emirates, it appears as though the Spaniard will largely have to make do with what he has got for the remainder of the season.
Whether Mesut Ozil comes into his thinking on a more regular basis remains to be seen, but the German is certainly out of favour at the moment and the fact that their highest earner did not even make the squad for last weekend's defeat to West Ham United is another major cause for concern.
Emery's Ozil omission is understandable when looking at the stats - he has contributed just three goals and two assists since signing a bumper new contract a year ago - but many fans will be scratching their heads at the refusal to hand Juventus-bound Aaron Ramsey fresh terms when reinforcements appear unavailable.
There is no shortage of problems to solve on the field too; last weekend's 1-0 loss to West Ham could have easily been plucked from the toxic end of Arsene Wenger's reign, and the Gunners have now been beaten four times in their last eight outings.
Only Fulham have kept fewer clean sheets in the Premier League this season, while goalkeeper Bernd Leno has only managed one in his 15 top-flight starts, and just six teams in the entire league have conceded more goals than the Gunners in total.
However, the bulk of Arsenal's problems this term have once again come on the road, and they are unbeaten in their last 10 league games at the Emirates Stadium in a run which stretches back to the opening weekend of the season.
Emery's side also boast an impressive record in home London derbies of late, winning each of their last five and remaining unbeaten in their last 12 since defeat to Chelsea three years ago.
Should they extend that record this weekend then they would be right back in the top-four race, but defeat to their capital rivals could be a fatal blow to their Champions League hopes while also giving Manchester United the chance to leapfrog them in fifth place.
Recent Premier League form: LWDLWL
Recent form (all competitions): WDLWWL
Much like his counterpart Emery, Chelsea boss Maurizio Sarri is beginning to find things a little more difficult now after a bright start to life in England.
The Blues face a crucial double-header with Saturday's visit to Arsenal being followed by a home game against Tottenham Hotspur next Thursday as they look to overturn a one-goal deficit in their EFL Cup semi-final.
Silverware would be within touching distance if they are able to beat Spurs at Stamford Bridge, but in terms of the league their focus is very much fixed on holding off another North London outfit in the race for fourth.
Victory this weekend would see Chelsea temporarily leapfrog Spurs into third, but more importantly it would open up a nine-point lead over Arsenal - and potentially Manchester United depending on results elsewhere - having capitalised on the Gunners' slip-up at West Ham by beating Newcastle United last Saturday.
However, Sarri will not be entirely happy having seen the goals dry up in recent weeks; Chelsea averaged 2.5 goals per game in their opening 11 league outings, but in their last 11 they have netted only 13 times and have not scored more than twice in any of those games.
The efforts to push through a move for Gonzalo Higuain in time for this weekend's match have failed, leaving Eden Hazard - without a goal since Boxing Day - to lead the line once again ahead of former Arsenal striker Olivier Giroud and the exit-bound Alvaro Morata.
There are fewer problems for Chelsea at the other end of the pitch with only Liverpool having kept more clean sheets and conceded fewer goals in the league this season.
The Blues have averaged more points per game on their travels than they have at Stamford Bridge too, and a victory this weekend would see them rack up four straight away league wins for the first time since December 2016.
However, they have won just one of their last nine league games away to other members of the top six, losing five of those including their only such one so far this season.
Recent Premier League form: WLWWDW
Recent form (all competitions): WWDWLW
Ozil was left out of the squad against West Ham last weekend, but Emery has insisted that the door is still open for the playmaker to work his way back into the team.
Whether he manages to do that in time for this match remains to be seen, but Arsenal will definitely be without Henrikh Mkhitaryan again as he enters the final stages of his recovery from a foot injury.
Rob Holding and Danny Welbeck are out for the remainder of the season, but Arsenal's general injury worries have eased significantly recently and the likes of Hector Bellerin and Nacho Monreal are in contention to return to the starting XI this weekend.
Pierre-Emerick Aubameyang is expected to start once again, having been directly involved in 20 goals in his 18 Premier League home games since joining Arsenal.
Hazard is likely to lead the line for Chelsea, with Giroud nursing a swollen ankle and out-of-favour Morata repeatedly being linked with a move away from the club.
Willian and Pedro were on the scoresheet against Newcastle and should have done enough to retain their starting roles, which means that Callum Hudson-Odoi will again be limited to a place on the bench.
Arsenal possible starting lineup:
Leno; Mustafi, Sokratis, Koscielny; Bellerin, Torreira, Xhaka, Kolasinac; Aubameyang, Lacazette, Iwobi
Chelsea possible starting lineup:
Kepa; Azpilicueta, Rudiger, Luiz, Alonso; Kante, Jorginho, Kovacic; Pedro, Hazard, Willian
Head To Head
Chelsea have lost just one of their last 14 league games against Arsenal, with that coming at the Emirates in September 2016.
Victory for the Blues this weekend would see them become the first visiting team to win six matches at the Emirates Stadium, although their most recent visit ended in defeat in their EFL Cup semi-final last week.
The two sides played out a dramatic 2-2 draw in the corresponding fixture last season, while the reverse match this term saw Chelsea win 3-2 after Arsenal had initially recovered from a two-goal deficit.
We say: Arsenal 2-2 Chelsea
Neither of these sides have been in the best form lately, but Arsenal simply have to go for the win in this match and that could leave their already-leaky defence even more vulnerable. It could go either way, but we're sitting on the fence with a draw which would suit Chelsea far better than it does the hosts.