The two sides, who hail from Bosnia-Herzegovina and Iceland respectively, have dropped down to this competition from the Champions League.
Match preview
After a dominant 2022-23 where they won the Bosnia top-flight crown by a mammoth 20 points, Zrinjski are now attempting to earn a place in the group stages of a European competition for the first time in their history.
The Nobles have had many near misses over the years, particularly last season when they lost on penalties to Slovan Bratislava in the Europa Conference League playoffs.
Coincidentally, the same opponents felled them in Champions League qualifying this time around, Zrinjski only making the aggregate scoreline respectable through two late goals.
Nevertheless, even though they are yet to play a domestic fixture this season, Krunoslav Rendulic's side have four matches under their belt ahead of what is one of the biggest matches in their history.
Whoever prevails from this two-legged tie is guaranteed a place in the Europa Conference League group stages as a bare minimum, and that pressure will also weigh on the shoulders of Breidablik.
This is just the fourth time in their history where they have reached the third qualifying round of a European competition, ensuring that one of these teams will break new ground over the coming weeks.
Although they initially defeated Shamrock Rovers, Breidablik lost out 8-3 on aggregate to Copenhagen in the Champions League second qualifying round, two of their three goals being scored when they were already 7-1 down.
Iceland's top flight is already nearing a conclusion before the Championship Round, Oskar Hrafn Porvaldsson's side sitting seven points adrift of top spot.
Blikar head into this encounter having failed to win any of their last four games in all competitions, conceding a total of 13 goals in the process.
Zrinjski Mostar form (all competitions):
Breidablik form (all competitions):
Team News
Captain Nemanja Bilbija was substituted during the second half against Bratislava last week due to injury and is an obvious doubt for this contest.
Tomislav Kis, who provided an assist in the latter stages, is a natural alternative, while Antonio Ivanic did his chances of a recall no harm by netting as a substitute.
Despite the size of their defeat to Copenhagen, Porvaldson may be against making any unenforced changes to his Breidablik XI.
Players were rested once the tie in Denmark was over as a contest, attention quickly turning to this tie.
Attackers Jason Dadi Svanthorsson and Kristinn Steindorsson both got on the scoresheet in that fixture and should retain their spots.
Zrinjski Mostar possible starting lineup:
Maric; Corluka, Jakovljevic, Barisic, Memija; Stanic, Canadjija, Ivanic; Cuze, Kis, Ticonovic
Breidablik possible starting lineup:
A.Einarsson; Gunnlaugsson, Muminovic, Margeirsson, Yeoman; Sigurjonsson, Ludviksson; Svanthorsson, Eyjolfsson, V.Einarsson; Steindorsson
We say: Zrinjski Mostar 1-1 Breidablik
Given the nerves that will be on show for this fixture, we expect a tense first leg. Zrinjski are in the better form when taking everything into consideration, yet we feel that the visitors will do enough to earn a share of the spoils.