The Polish side beat the Hoops convincingly over two legs but were disqualified from the competition for fielding an ineligible player
The Polish outfit beat the Hoops 6-1 on aggregate after dominating both legs of their third qualifying round clash, only to be disqualified for fielding an ineligible player.
Bartosz Bereszynski was brought on in the 86th minute but was meant to be serving a suspension after receiving a red card for violent conduct in last season's Europa League game against Apollon.
As a result, Uefa awarded Celtic a 3-0 second leg victory - meaning they advanced on away goals with the tie level at 4-4, setting up a final play-off clash against Maribor.
But Legia co-owner Dariusz Mioduski has now written to the SPL side in a bid to settle their fate in a one-off match.
"Meet in Warsaw or in Glasgow and let's settle this matter honourably," read a letter sent to Celtic Park on Sunday.
"The action is deeply unjust and contrary to the spirit of fair play."