What will be unusual about United's kit?
You may see something a little bit different when Manchester United play against Athletic Club at San Mames this evening (Thursday).
Ruben Amorim's men are wearing our blue change shirt, in order to avoid a clash with the red-and-white stripes of the hosts in Bilbao.
However, we will not be using the same-coloured shorts, as we have previously away to Southampton, Arsenal (twice), Nottingham Forest and Lyon.
For the Europa League semi-final first leg, we will be wearing shorts that are officially 'clear onyx' in colour, for the first time this season.
We have worn the socks previously, against Forest at The City Ground, with the silver feel to them.
The preference is for the Reds to wear a different contrast in shorts to the opposition, for instance lighter rather than darker, and Athletic Club wear black ones.
Fans will not have to wait long to see the shorts being worn again.
The same combination will be used for the Premier League clash at Brentford on Sunday afternoon, which kicks off at 14:00 BST.