The Frenchman has officially retired from the game this week.
The game is being played in the shadow of the League Cup final but there is no doubting it's significance to the Premier League season.
If Manchester United are to cling on to any hope of a top four finish they will need a win. Arsenal meanwhile would see their title hopes badly dented if they lost the game.
So it seems Arsene Wenger has pulled in a ringer to get involved in the sessions at London Colney.
Robert Pires, an Arsenal legend, retired from the game earlier this week. The former French international has been playing in India in recent years but has now decided to officially hang up his boots.
But he is still up for a kickabout.
He was spotted in training putting a friendly arm around Arsenal star and fellow Frenchman Francis Coquelin.
It is hard to know what advice Pires was giving the combative midfielder, considering how different the pair are in playing styles.
But hopefully Coquelin and the rest of the Arsenal players are soaking up his experience ahead of this big game.