Milner was probably United's most consistent player under Sam Allardyce, and such was the effect of losing Milner that Keegan changed his system from the 4-4-2 he has always preferred to the 4-3-3 formation which has proved to be an outstanding success.
Geremi, who has come in on the right side of midfield, could not be more different in style to Milner. But to be fair, the Cameroon international has been outstanding.
The problem is .... where will Milner fit in? He is versatile but is he too light-weight to fit into a three-man midfield that needs to be defence minded.
Having three out-and-out strikers, AND a winger, takes us back to the 1970 Brazilian World Cup winners with their 4-2-4 style that transformed football.
So many sides tried it, but none had Pele, Gerson, Tostao, Carlos Alberto or Jairzinho!
Keegan is already on record as saying that he will probably rely on the 11 players who started at Portsmouth on Saturday for Sunday, putting Milner on the bench.
And it could be a very interesting formation should Milner come on as sub.