Before every Arsenal fixture, we'll bring you a Scouting Report on the Gunners' next opponents.
Chelsea are the visitors to Emirates Stadium on Monday, to find out more, we asked Michael Cox and Simon Johnson.
Chelsea stuttered in their first few weeks of Jose Mourinho’s return - somewhat surprisingly, given his familiarity with the club and the Premier League overall.
But since then the Blues have become more disciplined without the ball and more purposeful in possession, and they would go above Arsenal with a victory on Monday.
Left-winger Eden Hazard is the Premier League’s most prolific dribbler this season, and has improved his discipline without the ballMichael Cox
Having favoured a 4-3-3 during his first spell in charge, Mourinho generally uses a 4-2-3-1 system now. He’s generally opted for physical defenders over more technical alternatives - Branislav Ivanovic has been used rather than Cesar Azpilicueta on the right, for example, although the Spaniard has now surprisingly displaced Ashley Cole at left back.
Chelsea are mobile and energetic deep in midfield, with the likes of Ramires and Frank Lampard. John Obi Mikel is another option, however, and brings more strength and positional discipline to the side - he might be used to stop Mesut Ozil finding space.
Mourinho has used quick, direct counter-attackers in advanced positions - Juan Mata has often been a substitute, with Oscar favoured because of his tactical discipline and his ability to use the ball efficiently.
Left-winger Eden Hazard is the Premier League’s most prolific dribbler this season, and has improved his discipline without the ball, too. Andre Schurrle is a similar option, while Brazilian wide midfielder Willian is yet another classic Mourinho player, quick and intelligent with his decision-making.
Up front, Mourinho has three dangerous options, but no Chelsea striker has scored an away league goal all season, and the Portuguese coach has yet to decide upon a clear first choice.
Fernando Torres doesn’t have the pace of old, but has improved his hold-up play and encourages attacking midfielders forward into attack - the key to Chelsea’s play in the final third. Samuel Eto’o is also slower than at his peak, but his movement is excellent and his runs would cause Arsenal’s centre backs problems, while Demba Ba is speedier and good at receiving long passes.
Overall, expect Chelsea to play reactively. Against Arsenal, Mourinho often asks his sides to sit deep before counter-attacking quickly with pace and power. Arsenal might control possession for long periods, but Mourinho’s sides are always most dangerous when given space to break into.
SIMON JOHNSON, EVENING STANDARD
The best word to describe Chelsea's season so far is inconsistent. You never really know which Chelsea will turn up at the moment and Jose Mourinho is clearly a frustrated manager because of that.
Their defeat against Sunderland in the League Cup was another disappointment. You could argue that that competition has showed the best and worst of Mourinho's side this season.
I'm sure Arsenal fans will remember that Chelsea were very good at the Emirates when they beat them 2-0 in the fourth round but at the Stadium of Light, against a team you would expect them to beat, they fell short.
Mourinho has never lost to Arsène Wenger and will want to keep that record going, so I think both teams will go for itSimon Johnson
There are quite a few differences between Mourinho's current squad and team he had in his first spell at the club. I don't think his current team are anywhere near as strong or as balanced as last time. It's also lacking strength of leadership and you could argue that the biggest miss of all for Chelsea is Didier Drogba.
They are missing a forward of that ilk and Mourinho has pretty much made it public that he's not very happy with the strikers that he has. They definitely miss a Drogba-type figure to make the difference in games and put their chances away.
John Terry has been the Blues' most impressive player so far. He had a difficult season last year as he was injured and then struggled to get in the team under Rafael Benitez. He was written off by a lot of people before the season started but he's been their most consistent performer and it's no coincidence he's started every league game for them this season.
Terry is leading by example but there just aren't enough characters like him to make the difference.
I'm expecting a very exciting game on Monday because both teams are coming into it knowing what's at stake in terms of their league position. Plus both sides have been on the end of disappointing defeats recently.
Arsenal will feel they can score goals against this Chelsea defence while Chelsea will be confident of repeating their performance when they won in north London in October.
Mourinho has never lost to Arsène Wenger and will want to keep that record going, so I think both teams will go for it. Chelsea will perhaps try and soak up Arsenal pressure in the opening 20 minutes and try to come on strong as the game progresses.
I'm expecting a really good game and I'm very much looking forward to it.Copyright 2016 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source