Ahead of their clash on Sunday, United's deadly attacking force, combined with the Blues' star-studded squad, could make the perfect, unbreakable team.
GK - Thibaut Courtois
The goalkeeping department is a source of strength for both sides, with David de Gea showing plenty of promise at Manchester United. But the combination of both Thibaut Courtois and Petr Cech makes Chelsea's shot stoppers the stronger overall. And Courtois is the best of the bunch.
LB - Cesar Azpiliceuta
If there are any United fans hoping to see a member of their back four make this combined XI, they are in for a long wait. At left-back, neither Marcos Rojo and Luke Shaw have imposed themselves. Cesar Azpilicueta, a natural right-back, is the top man in this position from both sides. After him, it's Filipe Luis.
CB - John Terry
Having recently captained his 500th game for Chelsea, John Terry is unbreakable at the moment. Nemanja Vidic or Rio Ferdinand could have beaten him in their prime - but not Phil Jones or Chris Smalling.
CB - Gary Cahill
Terry's team-mate at centre-back also makes the cut, making up for a relative lack of pace with a great reading of the game - a quality evident in many of the best defenders.
RB - Branislav Ivanovic
A sloppy game at West Brom aside, Rafael has been United's only good defender this season aside from youngsters Paddy McNair and Tyler Blackett, making this a close contest. But Branislav Ivanovic has been just as effective going forward and has been solid defensively over the years.
CM - Cesc Fabregas
CM - Nemanja Matic
Similarly, Louis van Gaal's outfit would look a different side with a holding midfielder as good as Nemanja Matic. Daley Blind has been a very good addition at Old Trafford, however.
CM - Angel Di Maria
Finally, a Manchester United player! The Argentine has been every bit as good as you could expect for a £59.7 million signing and the only thing that could make him even better would be stronger team-mates around him...
CF - Eden Hazard
Wayne Rooney is a player that's long been admired by Jose Mourinho - but he has nothing on the sheer skill of Eden Hazard on the ball (and is suspended for Sunday's clash, anyway). Hazard may be far from the final product but that enforces how scary the prospect of him at the top of his game will be.
ST - Diego Costa
Like Fabregas, an absolute phenomenon since moving from Spain. Unbelievably clinical in the Premier League so far, with his fitness being his only weak spot. Robin van Persie struggles from that too, however, and - on current form - which would you take?
ST - Radamel Falcao
Only the second United player to make it into this combined XI, Radamel Falcao is one of the world's leading strikers. He is yet to hit top gear at Old Trafford and yet his impact has already been clear for all to see. Without the Colombian, Van Gaal's men were nowhere near as threatening at West Brom.