Arsenal v Chelsea, Tuesday 21 January, 7.30pm, BT Sport 1 HD (CH 527)

Home or away, there was a period in the noughties when Chelsea dominated Arsenal. The Blues went ten games unbeaten against the Gunners between 2004 and 2007, with Didier Drogba bullying their frail defence. But recently, things have been very different.

Chelsea have only beaten Arsenal twice in the last nine attempts and haven’t won at the Emirates since January 2016. Thankfully for them, the man in the dugout was there throughout that dominant period. Few know better how to knock over the men from north London.

This will be Frank Lampard’s first taste of this derby as a manager, and he goes into it with his side in a strong position in the race for the top four. Arsenal meanwhile, are in danger of missing out on European football after a disastrous first half of the season.

Chelsea are on the verge of being able to strengthen their push by signing players for the first time in a year after their transfer ban was lifted, but it’s Arsenal who are in more dire need of strengthening. They are desperate for reinforcements in defence and midfield, with RB Leipzig’s Dayot Upamecano and Leicester’s Wilfred Ndidi possible targets. Meanwhile, Chelsea will be looking to strengthen up top. Timo Werner and Wilfried Zaha could both be on the shortlist.

Both sides’ January buying fortunes have been up and down. Here, we look at some of their most memorable purchases from this most entertaining of transfer windows. Click/hover on the players below to find out more…