The winners of this two-legged tie will progress to the newly-expanded 36-team Europa League, while the losers will drop down into the Conference League.
Match preview
FCSB are still in with a chance of qualifying for the main stage of the Europa League for the first time since reaching the knockout rounds in 2017-18 after rescuing a share of the spoils against LASK Linz in last week's first leg.
Adil Taoui opened the scoring for LASK just after the half-hour mark, but FCSB equalised through David Miculescu in the first minute of first-half stoppage time, before both sides struggled to pose a threat during a cagey second half.
FCSB have since extended their winless run in all competitions to four matches after they suffered a 2-0 away defeat to Hermannstadt in the SuperLiga on Sunday - their third top-flight loss in their opening six games of the new season that leaves the 27-time Romanian champions second-bottom of the table and already 10 points behind early leaders FC Universitatea Cluj.
Head coach Elias Charalambous suggested after the match that his players may have had one eye on Thursday's Europa League tie and that distraction ultimately played its part in a disappointing domestic performance.
The same can arguably be said about LASK, who have now lost three of their opening four Austrian Bundesliga games of the new season after losing 2-1 away against Austria Wien last weekend.
Marin Ljubicic has initially given Die Laskler a 19th-minute lead, but it was cancelled out just a minute later by Maurice Malone before Austrian Wien snatched all three points courtesy of an 87th-minute winner from Manfred Fischer.
Thomas Darazs was far from impressed with his side's performance and is now keen to see how his LASK players "deal with each other when the wind gets a little rougher" in the coming weeks, as the pressure mounts following a difficult start to the campaign.
A swift return to winning ways is high on the agenda for LASK, who enter Thursday's second leg seeking to qualify for the Europa League proper for the fourth time in their history and for the second time in as many seasons after competing in the 2023-24 group stage.
FCSB Europa League form:
D
FCSB form (all competitions):
D
W
L
L
D
L
LASK Linz Europa League form:
D
LASK Linz form (all competitions):
W
W
L
L
D
L
Team News
FSCB boss Charalambous has revealed that Darius Olaru asked to be taken off in the closing stages of the first leg with an unspecified issue. The attacking midfielder was not involved in last weekend's defeat to Hermannstadt and remains a doubt for Thursday.
The potential absence of Olaru, who has recorded seven goals and three assists in 11 games this term, could see Alexandru Baluta deputise in the number 10 role behind Daniel Popa, with support to be provided in attack by Miculescu and Florin Tanase.
As for LASK Linz, Andres Andrade (ACL), Ibrahim Mustapha (ankle), Florian Flecker (broken leg), Maximilian Entrup (knee) and Ivan Ljubic (hamstring) all remain sidelined with injuries, while Tomas Tavares is a doubt.
Tomas Galvez, a loan signing from Manchester City, recovered from a minor issue to feature as a second-half substitute last weekend and the teenager could be fit to start ahead of George Bello at left-back.
FCSB possible starting lineup:
Lawal; Bogarde, Ziereis, Smolcic, Galvez; Jovicic, Horvath; Usor, Zulj, Pintor; Ljubicic
LASK Linz possible starting lineup:
Tarnovanu; Cretu, Ngezana, Dawa, Radunovic; Sut, Edjouma; Stefanescu, Baluta, Tanase; Popa
We say: FCSB 1-2 LASK Linz (LASK Linz to win 3-2 on aggregate)
Positive results have been hard to come by for both teams in recent weeks, but they will both be motivated by the prospect of securing their spot in the Europa League with a victory on Thursday.
FCSB have lost three of their last four matches on home soil and they may come up short once again in front of their own fans, as we are backing LASK Linz to edge a closely-fought second-leg contest.