It's complicated, bear with us.
Manchester United currently sit top of Group A in the Champions League on 12 points but it's still possible that José Mourinho's side will crash out of the competition tonight.
Here's how.
CSKA Moscow and Basel both have 9 points at this moment in time, with CSKA coming to Old Trafford tonight and Basel travelling to Lisbon to face Benfica, who are guaranteed to finish bottom.
If Basel and CSKA win their respective matches tonight, they will both be tied with United on 12 points. However, in the Champions League, the head-to-head record between clubs is the first tiebreaker, as opposed to goal difference.
This will mean the top two is decided by a three-way head-to-head. Still with me? Good.
https://twitter.com/MarcoReubs/status/938004944862547968?ref_src=twsrc%5Etfw&ref_url=https%3A%2F%2Fcms.joe.co.uk%2Fwp-admin%2Fpost.php%3Fpost%3D151840%26action%3Dedit
Now, to prevent United from qualifying, CSKA must beat them by 7 goals, and Basel must also win in Portugal.
This would mean that, due to Basel beating CSKA in their head-to-head battle, and the Russian side's theoretical 7-0 victory lifting them above United in the head-to-head mini league, the Red Devils would come third in the group and drop into the Europa League.
With a Premier League title to chase, that would not be ideal. We all know the physical toll a Thursday-Sunday schedule can have on a squad.
It's unlikely, but stranger things have happened - probably - and with a Manchester derby coming up at the weekend, Mourinho might just field a weakened side.
