Celtic's place in the Champions League play-offs was confirmed after Legia Warsaw failed in their final bid to be reinstated in the competition.
Less than 24 hours before Celtic fly out to Slovenia for their first leg against Maribor, the Court of Arbitration for Sport (CAS) rejected the Polish champions' appeal to be provisionally reinstated in Europe's premier competition.
The Swiss-based court will hear more detailed legal arguments from Legia but the Poles are now looking for compensation and what they describe as "justice for football" to make sure that no other teams face similar sanctions for mistakenly fielding a suspended player.
In Legia's case, Bartosz Bereszynski came on in the 86th minute of their 2-0 second-leg win at Murrayfield, turning a 6-1 aggregate victory into an away-goals defeat after Uefa acted on its rules that clubs forfeit games for fielding ineligible players.
The Poles were already resigned to playing in the Europa League before the decision was announced and now travel to Kazakhstan to face Aktobe in a bid to qualify for the group stages of that competition.
Legia were previously angered by Uefa's refusal to sanction a fast-track CAS hearing after the European governing body's appeals body upheld its disciplinary panel's ruling that Ronny Deila's side be awarded a 3-0 second-leg win over the Polish side.
And the Lausanne court denied their "urgent request for provisional measures" to be reinstated into the Champions League.
CAS revealed that the president of its appeals arbitration division had considered written submissions after both Uefa and Celtic were invited to give their opinions on Legia's appeal.
A statement added: "The CAS arbitration will now continue and a panel of arbitrators will be constituted to examine this case within the next weeks.
"On the merits, Legia has requested that no sanctions be imposed on either the club or the player Bereszynski and that Uefa be ordered to pay a financial compensation to the Polish club."