The Gunners are in the market for a striker.
With only Olivier Giroud as a first team striker at the club, the Gunners have been linked with several new forwards but whether they can actually sign any of them is another matter.
Likely cost: £27m.
The Frenchman is not a favourite of new Real Madrid head coach Carlo Ancelotti and the manager would probably let the 25-year-old leave.
However, a replacement would have to be found first with Liverpool’s Luis Suarez looking the most likely.
Chance of coming to north London: 7/10.
Likely cost: £20m.
What a season it has been for the 25-year-old, who has taken up the mantle left by Radamel Falcao with gusto and already has 15 goals in just 16 games.
Borussia Dortmund are the only other club likely to ruin Arsene Wenger’s chances, but Costa seems happy at the Vicente Calderon Stadium.
Chance of coming to north London: 5/10.