Rangers manager Ally McCoist bemoaned a series of missed chances as his side exited European competition.
A 1-1 draw at Ibrox with Maribor gave the Slovenian side a 3-2 aggregate win to progress to the group stages of the Europa League.
"We weren't good enough in terms of taking our chances," said McCoist.
"You can't miss chances that we missed over the two legs and expect to go through. The lads are bitterly, bitterly disappointed, as we all are."
Nikica Jelavic, Maurice Edu and Kyle Lafferty all missed first-half opportunities and Maribor capitalised at the start of the second half when Dalibor Volas cancelled out Rangers' away goal from the first leg.
Carlos Bocanegra levelled on the night for Rangers but McCoist's men fell short of getting the goal that would have forced extra-time, David Healy missing the best of the late chances.
"In terms of their attitude, desire and effort, I think they've given us just about everything," McCoist told BBC Radio Scotland. "They kept going right until the final whistle.
"We missed chances tonight to win a couple of games and having been in that situation myself on numerous occasions, I know how disappointed the boys will be.
"The second 45 minutes in Maribor cost us the tie."
McCoist has now overseen qualifying exits from both European competitions, Malmo having beaten Rangers on aggregate in the Champions League.
"We've been here before," McCoist said. "You sink or you swim and sinking's not an option, so you swim and we get back in tomorrow and we start swimming again and we'll get on with it.
"We all have to stick together, every one of us, whether it's the players, the management, the fans. We've all got to regroup, stick together and we'll get through this.
"I don't feel any more pressure than I did when I took the job right at the start. The pressure is to win games for Rangers. In Europe we haven't done that, there's no getting away from it so there is pressure to win games.
"I'm disappointed more than anything, that's my overriding feeling at this moment in time.
"I certainly would not want to be disrespectful and say they're not a great side. They were good enough to beat us over the two games so good luck to them, you wish them well in the tournament.
"But, if you're asking me were they a side I felt we should've beaten, yes.
"We'll be ready for Aberdeen on Sunday. We've got a league championship to retain and we'll be doing everything we can to do that."