Martin Keown has now warned Arsenal to protect one player at all costs ahead of this weekend’s tie with Tottenham Hotspur. Mikel Arteta and his side will certainly be on a high right now having beaten London rivals Chelsea 5-0 last night. The victory felt decisive not only in terms of the three points and the confidence it provokes, but Arsenal definitely now know their strongest side. Perhaps some personnel are still interchangeable, Gabriel Martinelli could easily replace Leandro Trossard for example. But it’s now clear that Thomas Partey needs to play in the pivot and Kai Havertz as the fal…