The Istanbul giants claimed a famous win at Old Trafford last month but have failed to cement their status as the heir to second place in Group A.
In fact, it is unfancied Copenhagen ahead of both of these teams before they take to the pitch in the early evening kick-off.
United are only a point behind both Gala and the Danes, meaning a win tonight is vital before finishing off their group campaign at home to Bayern Munich.
The Red Devils have improved domestically since that shock in Manchester but are up against a Galatasaray team which has only been beaten by Bayern and Hatayspor all season.
Where to watch Galatasaray vs Manchester United
TV channel: In the UK, tonight's game will be televised live on TNT Sports 1, with coverage beginning at 5pm GMT. Kick-off is set for 5.45pm.
Live stream: Subscribers can also catch the contest live online via the Discovery+ app and website.
Live blog: You can follow all the action on matchday via Standard Sport’s live blog.