Can Olivier Giroud continue his fine run of form in front of goal and end Arsenal's barren run against Chelsea? John Terry will be out to stop him...
Some things never change. No matter how unpredictable Chelsea's decline, their Premier League hoodoo over Arsenal remains constant. The Blues are unbeaten in eight league meetings against their north London rivals.
Arsenal haven't even scored in the last five league meetings - this Wednesday was the third anniversary of their last league goal, in a 2-1 defeat at Stamford Bridge. Alex Oxlade-Chamberlain's winner in the Community Shield was less a power shift, more a statistical aberration.
This is a record title hopefuls Arsenal could do with ending - so it's just as well Giroud has found his top form.
The striker has scored nine goals in his last 10 games, including two at Anfield, the winner against Manchester City, and a hat-trick in a do-or-die Champions League game at Olympiakos. Go back to mid-October, and Giroud has scored 18 times in 23 games for club and country.
This is promising, but while Arsenal have struggled against Chelsea, so has Giroud. The Frenchman has failed to score in six Premier League appearances against the Blues.
He has actually found the net against 20 of the 25 Premier League teams he has faced, but Chelsea are the only side he has played more than twice and failed to score against.
So how could Arsenal and Giroud find the net against Chelsea this weekend?
Giroud has scored five league headers this season - only Gareth Bale has scored more in Europe's top five leagues - but he's more than just a battering ram.
Crossing to a big man in the box might not seem like Arsenal's style, but Mesut Ozil is one of just 14 players to have attempted over 100 crosses or corners in the Premier League this season. His 41.03 per cent accuracy is comfortably the best of any player who has attempted 50 or more, and three of Giroud's five headers this season have come from Ozil crosses.
But Chelsea, and specifically Terry, know how to handle aerial threats, right?
The struggling champions have already conceded seven top-flight headers this season compared to just six in the whole of last term. In 2014/15, only three teams conceded fewer headers than Chelsea - in 2015/16 so far, only Everton, Norwich and Newcastle have conceded more.
Last season, Chelsea won 54.35 per cent of their aerial battles, the second best record in the division. This campaign they've won 51.02 per cent - enough to drop them down to tenth. Arsenal have been a little more consistent - they had the third-best record last season and the second-best this term.
However, recent history suggests Terry and Chelsea have what it takes to defend Arsenal's aerial attacks.
In last season's 0-0 at the Emirates, Arsenal recorded just seven shots on goal - their fewest in a home Premier League match since December 2013. They did attempt 31 crosses - well above their seasonal average of 22.79 per match - but completed just two. Terry and Gary Cahill made 11 headed clearances between them.
But there may be reason to believe this game will be different. Terry has made 35 headed clearances in 17 top-flight appearances this season, just over two-per-game. Over the previous five seasons, from 2010-15, he averaged 3.63-per-game.
This campaign he's won 68.5 per cent of aerial battles - not terrible, but short of his rivals and down on Terry's own 72.8 per cent from last season. He's not as dominant aerially as he used to be.
Given Arsenal's new-found aerial threat and Chelsea's struggles, maybe things are about to change after all…