Celtic will have to leave at least one of their new first-team signings out of the squad to face Bodo/Glimt in the Europa Conference League.
And Ange Postecoglou will have to decide tonight on which of Reo Hatate, Matt O'Riley, Daizen Maeda or Yosuke Ideguchi will miss out.
Those four along with B-team striker Johnny Kenny completed Celtic 's January business as Postecoglou added significant depth to his squad.
However UEFA rules mean that only three new players can be added to the squad ahead of the knockout stage - which kicks off for Celtic against Bodo/Glimt on Thursday 17 February.
Osaze Urhoghide, Liam Shaw, Adam Montgomery and Ewan Henderson have freed up slots in the squad as they headed out on loan last month, though some occupied B-list places. Irrespective of that, only three new eligible players can be named in the squad for the knockout round play-off.
The deadline given for final squad lists is 11pm on 2nd February - meaning there are just hours remaining before a decision has to be made.
Postecoglou will certainly want Hatate available as he has established himself as a crucial cog in midfield in the absence of Callum McGregor.
Hitman Maeda also made his mark with a debut goal against Hibs while Matt O'Riley has proven himself capable in midfield with a man-of-the-match display against Hearts.
Ideguchi meanwhile is out with an injury sustained against Alloa so he seems the most likely of those four to miss out, while striker Kenny continues his development with the B-team.
Celtic face the Norwegian side at Parkhead first on February 17 before travelling to Bodo for the second leg a week later on February 24.
