How do the records of Juan Mata and Oscar compare this season?
Mata was sold by Chelsea to United in January 2014, and has taken on his old side three times since then, failing to end up on the winning team.
The last three games have been 1-1 and 0-0 draws, with a 1-0 defeat to the Blues at Stamford Bridge last season.
United return to west London this weekend hoping to get a result against Guus Hiddink's side, in a battle of Dutch bosses.
Mata was sold by Chelsea because of their commitment to playing Oscar in the role behind the striker, but like most players at the club this season, the Brazilian is experiencing an underwhelming campaign.
Manchester United ace Mata has one more Premier League goal to his name than Oscar this season, and one more assist, while also creating more goalscoring chances per game
He has also recorded a pass completion rate of 89 per cent, nine per cent higher than Oscar - although the Chelsea attacker has been more successful when it comes to winning individual battles, more than doubling Mata's success.
The Spaniard has plenty of positive Stamford Bridge memories, and many Chelsea fans were upset to see him leave two seasons ago.
He is due a big performance against his former side, while Oscar will be keen to show why Chelsea blocked a £57 million bid from Jiangsu Suning for his signature, report The Sun.