Celtic boss Brendan Rodgers turned his attention to the Europa League after finding Champions League football "a step too far" this season.
The Northern Irishman, who had taken the Hoops to the group stages of the competition in his first two years in charge, had admitted the second-leg of the third qualifier against AEK Athens in the Olympic Stadium on Tuesday night was his biggest qualifying challenge to date following the 1-1 draw at Parkhead last week.
Within six minutes his side were a goal down through a Rodrigo Galo strike, with Croatian striker Marko Livaja heading in a second five minutes after the break.
Parkhead substitute Scott Sinclair pulled a goal back in the 78th minute but despite a grand finale the Scottish champions could not fashion a second which would have put them through on away goals.
The Scottish champions drop down to the Europa League play-off, where they will face Latvian side Spartaks Jurmala or Lithuanian side Suduva, and Rodgers said: "The Europa League is still a prestigious competition.
"The two seasons I've been here, we've qualified for the Champions League but it's been a step too far this season.
"First of all, we have to get through that final play-off game and ensure that we have European football.
"At this moment in time we're disappointed with the result of the game and the way we went out. "
Rodgers bemoaned some slack defending for their Champions League exit.
He said: "I think in general, in the game, we played very well but we conceded two soft goals.
"When you add that to the goal we conceded in the first leg then we're really disappointed.
"Lots of our game I thought we played the better football over the course of the two games.
"In the main, there weren't too many opportunities against us but you can't concede that easily and unfortunately it's cost us.
"I thought we were the better football team over the two legs."
Meanwhile, Rodgers claimed Dedryck Boyata had been fit to play.
The Belgium defender, subject of a failed £9million bid by Fulham before the English transfer window closed, had posted a video of him receiving treatment before the game in Greece.
His agent Jacques Lichtenstein was quoted earlier in the week by DH.be saying that as his client is in the final year of his contract, he could not risk playing when not 100 per cent fit.
Rodgers, who was also without suspended defender Kristoffer Ajer, said: "Yes, we were obviously missing our two best centre halves this evening unfortunately.
"My concentration really until I get back is only with the players that are here.
"But yes, Dedryck would have been fit to play."
Asked if he felt frustrated on a night where defensive inadequacies proved costly, he said: "Yes, of course. He has been with us on the journey now for a couple of years and helped us get to this position and of course, someone of his quality, a World Cup semi-finalist in our team, would certainly would have helped.
"But he wasn't here and we look at the performance without him and I can't think any more than that".
