European football’s governing body have announced that the appeal will be dealt with at a hearing on 13 August.
The Polish side hammered Celtic 6-1 on aggregate in the third qualifying round of Europe’s premier club competition.
But they were subsequently eliminated from the tournament as a result of them bringing on defender Bartosz Bereszynski in the second leg when the player was supposed to be suspended after he was sent off for violent conduct against Apollon in the final match of Legia's Europa League campaign last season.
As a result, the match was declared a 3-0 forfeit, making the aggregate score 4-4, and giving the Scottish champions the tie on away goals.
The situation is complicated further by the fact that the player missed both ties against St Patrick's in the second qualifying round and then sat out the first leg against Celtic.
But UEFA decided he had not been registered in Legia's squad for the games against the Irish side in order to allow a three-match suspension to take effect.In the Champions League draw which followed the ruling, Celtic were paired with Maribor of Slovenia for a place in the group stages of the competition.