Dutch giants Ajax await either side in the final stage before the competition's group phase, which Ludogorets have reached in every one of the last six years.
Match preview
Having gone one goal ahead in last Thursday's contest in the Kazakh capital, Ludogorets then let their lead slip shortly before the break, and within the space of 15 minutes either side of half time they found themselves 2-1 behind.
After Noah Sonko Sundberg struck in the 34th minute at Astana Arena, the home side replied with goals from Zarko Tomasevic and Aleksandr Marochkin to take a valuable advantage with them to Bulgaria for this week's return.
Ludogorets slipped out Champions League qualifying earlier this summer, after winning their 12th straight domestic title in June, when a dramatic final matchday saw their 1-0 win away to Cherno More pip second-placed CSKA Sofia to top spot by a single point.
Despite progressing past Ballkani in the opening round, Ivaylo Petev's side then crashed out to Slovenian champions Olimpija due to conceding a decisive stoppage-time goal in Ljubljana.
The Eagles recently started their new top-flight campaign with a shock opening loss, quickly followed by two 5-0 wins; Sunday's emphatic 3-0 success against CSKA - acheived despite Sonko Sundberg being sent off during the second half - has further brightened the mood.
Although they have often exited before the knockout stage, Ludogorets have been a recent fixture in the Europa League's autumn phase, but in order to keep their hopes alive this year they must now fight back from behind against a club boasting similar pedigree.
Having also dropped out in the Champions League's second qualifying round earlier this month, Astana are now seeking to reach a European group stage for the sixth time since 2016.
While Ludogorets finished third behind Real Betis and eventual finalists Roma in Europa League Group C last term, the champions of Kazakhstan have been knocked out in qualifying for various UEFA competitions in each of the last three years.
After being crushed 6-0 on aggregate by Dinamo Zagreb to end their pursuit of a Champions League place, Grigori Babayan's side now find themselves 90 minutes away from meeting Ajax at the end of August - an improbable victory in that tie would then send them into the group stage.
Midway through the defence of their national title, Astana lie six points adrift of Kazakhstan Premier League leaders Ordabasy, but having been spared a weekend fixture they should now arrive in Razgrad with fresh legs and real hope of setting up a trip to Amsterdam.
Ludogorets Razgrad Europa League form:
L
Ludogorets Razgrad form (all competitions):
Astana Europa League form:
W
Astana form (all competitions):
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Team News
Chasing goals in order to turn the tie around, Ludogorets could make changes to the team that was beaten 2-1 last week. Both second-half substitutes in Astana, wingers Caio Vidal and Spas Delev head the queue for promotion from the bench.
Ivalyo Petev is still unable to call upon suspended Spanish full-back Son, however, while Swiss striker Kwadwo Duah - signed from Nurnberg earlier this summer before providing two assists on his debut - is absent due to an ankle injury which will keep him out until September.
As Noah Sonko Sundberg's upcoming ban only applies to domestic competition, the the ex-Ostersunds defender should helm the hosts' defence, in which Son's absence at left-back is set to be covered by Marcel Heister.
Astana, meanwhile, have benefited from a week's rest since the first leg, so are expected to name a similar starting XI on Thursday.
Abzal Beysebekov would therefore captain the away side from the heart of a five-man defensive line, alongside first-leg goalscorers Aleksandr Marochkin and Zarko Tomasevic; Gambia international Dembo Darboe starts up front.
Ludogorets Razgrad possible starting lineup:
Padt; Witry, Russo, Verdon, Heister; Goncalves, Piotrowski; Vidal, Despodov, Tekpetey; Tissera
Astana possible starting lineup:
Condric; Hovhannisyan, Marochkin, Tomasevic, Beysebekov, Vorogovskiy; Tomasov, Loncar, Ebong, Ourega; Darboe