The hosts narrowly defeated FC Corvinul Hunedoara in the last round, while the visitors have comfortably beaten Pafos FC and Sheriff Tiraspol to make it to this stage.
Match preview
Rijeka had their best season since last winning the HNL title in 2016-17, finishing in second place with 74 points from 36 matches, eight points behind the eventual champions Dinamo Zagreb.
Zeljko Sopic's side were top of the league going into the final five matches, but a disappointing run of four defeats before winning 4-0 on the last day saw them give up the position to the champions.
Sopic also saw his men suffer a 3-1 aggregate defeat in the final of the Croatian Cup during that poor stretch of results, something the manager will be determined to put right with triumphs this campaign.
They are undefeated in their opening three competitive matches of this term, although they only narrowly progressed past Corvinul Hunedoara in the second qualifying round before convincingly beating NK Lokomotiva Zagreb 4-0 in their first league game.
Rijeka will now face Elfsborg in their biggest test of the campaign so far, aiming to ultimately progress through to the Europa League for the first time since finishing bottom of Group F in 2020-21.
Elfsborg also had a positive yet heart-breaking last season, finishing level on points with champions Malmo but finishing as runners-up due to a worse goal difference, denying them their first league title since 2012.
They have, however, failed to reach those heights this year, disappointingly sitting seventh in the Swedish Allsvenskan after 17 matches played, already a significant 13 points behind league-leading Malmo.
Oscar Hiljemark was appointed in June as Jimmy Thelin left for Aberdeen, and the new manager has been able to improve their form, winning seven of his eight matches in charge.
While Hiljemark will be looking to continue that positive run in this game, he will be aware of his side's struggles away from home this campaign, managing just two away wins from eight league matches on the road.
HNK Rijeka Europa League form:
D
W
HNK Rijeka form (all competitions):
Elfsborg Europa League form:
W
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Elfsborg form (all competitions):
W
W
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L
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Team News
The hosts are expected to be unable to call upon the services of Bruno Goda or Martin Zlomislic after both picked up injuries that will keep them out for several weeks.
Dejan Petrovic scored the only goal of their second qualifying round tie with Corvinul Hunedoara and the midfielder is likely to play a big part in this game as well.
The visitors have avoided any fresh injury concerns in recent weeks, leaving Hiljemark with a fully fit squad to choose from, and the manager could opt to name the same side that beat Sheriff Tiraspol last time out.
Michael Baidoo, who scored in that 2-0 win, is Elfsborg's joint top-scorer in the league with five goals, and the attacker is anticipated to start in this one.
HNK Rijeka possible starting lineup:
Posavec; Smolcic, Galesic, Radeljic, Cabraja; Pasalic, Petrovic, Selahi, Fruk, Jankovic; Ivanovic
Elfsborg possible starting lineup:
Pettersson; Holmen, Henriksson, Yegbe; Hedlund, B Zeneli, Ouma, Hult; A Zeneli, Baidoo, Abdullai
We say: HNK Rijeka 1-1 Elfsborg
Elfsborg may have struggled away from home this season, but they have secured three consecutive away wins in their most recent outings. Meanwhile, the hosts are still finding their rhythm after their season started in recent weeks, suggesting this match will end in a draw.