The side that prevails over the two legs will go on to face either Slovan Bratislava or Struga in the second qualifying round.
Match preview
Flora are set to make a second consecutive appearance in Champions League qualifying after retaining their Meistriliiga title last season.
Jurgen Henn left his position as manager following the end of last season, paving the way for Norbert Hurt to begin his second spell as Flora manager.
Hurt will be disappointed with Flora's league campaign, with his side currently sitting in third place and 15 points adrift of runaway leaders Levadia with 16 games left to play.
Incidentally, Hurt's charges lost 1-0 to Levadia in their most recent outing, bringing an end to a seven-game unbeaten run.
They will now turn their focus to European competition, and they will be hoping for a better outcome than last season's 4-0 aggregate defeat to Rakow in the first round of Champions League qualifying.
While Flora are in the middle of their season, Celje will officially begin the 2024-25 campaign when they take to the pitch at the Lillekula Stadium in Tallinn.
They will have fond memories of the 2023-24 season after they collected 79 points from 36 matches to win the Slovenian PrvaLiga title for just the second time in their history.
As a result of their league performance, Celje can look forward to participating in Champions League qualifying for the first time since 2020-21.
On that occasion, they got the better of Dundalk before losing to Norwegian side Molde in the second qualifying round.
They are still waiting to make their first main draw appearance in a major UEFA competition after falling just short in last season's Europa Conference League, where they were eliminated by Vitoria de Guimaraes and Neman Grodno before losing to Maccabi Tel Aviv in the playoff round.
Flora form (all competitions):
Celje form (friendlies):
Team News
Flora left-back Marco Lukka is in line for a recall after dropping down to the bench for Thursday's defeat to Levadia.
Mark Anders Lepik will pose one of the home side's main attacking threats, having scored 17 goals in 24 competitive appearances this season.
As for the visitors, they are expected to be without right-back Zan Karnicnik, who has recently finished representing Slovenia at Euro 2024.
Aljosa Matko will be given the chance to lead the line after scoring 20 goals in 32 competitive matches last season.
Flora possible starting lineup:
Grunvald; Hussar, Kolobov, Tougjas, Lukka; Zenjov, Kreida, Mihhailov, Kuraksin; Lepik, Alliku
Celje possible starting lineup:
Rozman; Ajhmajer, Zec, Vuklisevic, Milic; Menalo, Svetlin, Zabukovnik, Bobicanec, Brnic; Matko