Celtic have been reinstated to the Champions League after Legia Warsaw were punished for fielding an ineligible player.
Legia won the third qualifying round tie 6-1 on aggregate but brought on Bartosz Bereszynski in the second leg, while he was supposed to be suspended.
As a result Celtic were handed a 3-0 'walkover' win for the second leg, taking them through on away goals.
Celtic will play Maribor of Slovenia in the play-offs later this month.
And Legia Warsaw have been drawn to play Aktobe of Kazakhstan in the Europa League play-off.
"It is very strange, I have to say that," said Celtic manager Ronny Deila, whose Norwegian countryman Henning Berg is in charge of Legia.
"First of all I feel very sorry for Legia, and my friends from Norway there. It is tough to think of that and now we are in the Champions League.
"Legia played well against us, they put in good performances but this is nothing to do with Celtic. It is about UEFA.
"It is not my business. It is a club thing and a UEFA thing.
"It is a tough decision and I really feel sorry for Legia but we have to go into the game and prepare for Maribor.
"The players want to play in the Champions League. It looks like we have been given another chance and I think it will be no problem to get the players up for the game."
Legia have five days to appeal and have asked for Uefa's reasoning.
The Polish champions, who now take Celtic's place in the Europa League play-offs, won the first leg 4-1 and the second 2-0.
The disciplinary board of European football's governing body Uefa confirmed that Bereszynski has also been hit with a further one-game suspension.
He was sent off in Legia's final Europa League tie last season against Apollon Limassol and received a three-match ban.
He missed the club's two-legged tie against St Patrick's Athletic in the second qualifying round and the 4-1 first-leg victory over Celtic.
However, it has emerged that Bereszynski was not registered in Legia's squad for the ties against the Dublin side and therefore the matches did not count towards his suspension.
Legia official Dominik Ebebenge said: "This is unjust and completely disproportionate.
"There have been similar cases in the past which have not punished in this way. This was just a basic human error.
"We have spent eight years working towards this and now it has been taken away from us. Financially, it's unimaginable and the players are shattered."
Celtic have previously been given a reprieve in continental competition in similar circumstances.
Neil Lennon's side were beaten 3-1 on aggregate by Sion in the Europa League three years ago, but the Swiss side were subsequently ejected from the competition after they were found to have fielded ineligible players.
Sion had signed five players while still under a Fifa transfer ban for breaching rules over the signing of Egypt goalkeeper Essam El-Hadary three years earlier.