There may be a silver lining to Zlatan Ibrahimovic's three-match suspension for elbowing Tyrone Mings last weekend. He's 35 and was going to need a rest at some stage.
Manchester United have not exactly used him sparingly this season because they can't afford to.
He has to play for them to be anywhere near winning the big games. But if they can get by without him in this period, with an international break also approaching, it could help as they pursue a place in next season's Champions League - by finishing in the top four of the Premier League or winning the Europa League.
I was at Stamford Bridge when Chelsea beat United 4-0 in the league last October and they can do that again. They have a ruthless professionalism about them and will see this as another chance to have a psychological advantage over United that could linger into next season. A chance, at home, to knock them out of the FA Cup.
They wouldn't want to play United in the final, so they'll be happy to have this game now with the form they are in. It's only good news for them that Ibrahimovic is not going to play.
Manchester United have not exactly used (Ibrahimovic) sparingly this season because they can't afford to.
He has to play for them to be anywhere near winning the big games.
What happened to Jose Mourinho at Chelsea will have hurt him. Everyone is politically correct these days, nobody says anything out of turn, but some players downed tools on him and got him out.
That's a mark of where the game is right now. The tail wags the dog. One of the biggest managers in world football can be manoeuvred out the door by player power, as Claudio Ranieri was at Leicester, and that will have hurt Mourinho.
He has a much better relationship with Ibrahimovic. At the start of the season, I said that if United were going to have a good one, it would be down to Ibrahimovic. That's how it has turned out. He's their main man.
It's not just the quality he gives you on the pitch - in any team you need leaders. If you have one, you're lucky and have a chance of winning trophies because the lesser lights will come in behind him. It gives belief to the others to perform. Those players are few and far between and he's got that, so he's an enormous loss to United.
Maybe Mourinho will ask Wayne Rooney to step up. He didn't take him to Russia for the Europa League match against Rostov, so he's the obvious one to come in. He has not prospered in the shadow of Ibrahimovic, which has surprised me. I thought he would rise to the challenge of playing with him.
Rooney has been the main man, then someone comes in who has been as successful as him and he's not responded. With Ibrahimovic out, we'll find out where Rooney is in the pecking order and whether he'll be at United next season.
For United to win, they'll have to have a special night, but Chelsea just grind results out. When they are not at their best, they still win games. There's no obvious weakness. They have cover in midfield, at the back and for goalkeeper Thibaut Courtois.
The only vulnerability I see is if Diego Costa gets a bad injury, but if there were no Costa and no Ibrahimovic on Monday, you would still fancy Chelsea.
THE TIMES, LONDON