Former boss Neil Lennon insists all the focus at Celtic will now be on dethroning Rangers in the league this season.
The hopes of a return to the Champions League group stage were brought to an abrupt end on Wednesday in qualification defeat to Midtjylland.
Ange Postecoglou will have a second chance at European football with the Europa League qualifiers just around the corner, bur Lennon doesn't see that as key for the club.
The Northern Irishman reckons his successor will now turn his attention to a Premiership title tilt rather than look at a push in the Europa League.
He told BBC Five Live that work has to be done quickly to assemble a squad that can challenge Steven Gerrard 's men next term.
When asked for an insight on where the priorities are for Celtic ahead of their first game on Saturday, Lennon said: "I think the league is the priority now.
"When you go into any season with Celtic you are looking at the Champions League being your first target.
"If that's a success, then great. The club will have budgeted for being in the Champions League and not being in the Champions League. The next priority is the league.
"They will look to build a squad now to challenge Rangers.
"Rangers are definitely, at the minute, comfortable. They need to put a challenge in to Rangers.
"The mentality shift is there for everyone to see, but now all the pressure will be on Rangers going into the season.
"But Celtic need to build a squad robust and strong enough to challenge that, but the league will be the priority I would imagine."
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