Manager Brendan Rodgers revealed his higher expectation of his Celtic side after they won through to the Champions League play-off with a 1-0 aggregate win over Rosenborg on Wednesday night.
On a tense evening in Trondheim, makeshift centre-forward James Forrest's second-half strike was enough to take the Scottish treble-winners past the game but limited Norwegian side - 1-0 on aggregate.
The Parkhead club reached the group stages of the competition last year in Rodgers' first season as Hoops manager and he believes the improvement since then will be significant when they move into the final eliminator.
Celtic will face either, Qarabag, Astana, Rijeka, Slavia Prague or Hapoel Beer-Sheva in the play-off and the former Swansea and Liverpool boss said: "When the draw comes it is going to be one of those anxious moments again at some point over the two legs.
"But like I say, 12 months on it is a different mentality and feel.
"The squad are happy to go through but as I now expect that - and that comes from the belief of how they work and how they play.
"Whoever we get it will be a tough game and my focus now will be on Hearts (on Saturday)."
Rosenborg manager Kare Ingebrigtsen claimed his side should have taken advantage of the chances they had in last week's first leg at Celtic Park.
He explained: "We should have scored in Glasgow, that's where we lost it.
"We gave Celtic too much respect in the first 45 minutes, the last 45 minutes we handled much better.
"We put some pressure on them but in the best period of our game they scored a goal, it is a clinical finish.
"Over two legs it was small margins."