The Finnish side are looking to avoid a fourth consecutive elimination in the second qualifying round, while Plzen are aiming to win at this stage of the competition for the first time since the 2013-14 season.
Match preview
Plzen are dreaming of a first Champions League group stage appearance since the 2018-19 campaign, but they have a long way to go in qualifying if they are to realise that dream.
In the short-term, Plzen will take a narrow lead into the second leg on Tuesday after beating HJK 2-1 in Finland last week.
Tomas Chory got his side up and running from the penalty spot in the sixth minute before they were pegged back by a Bojan Radulovic equaliser five minutes after the restart.
However, Plzen required just seven minutes to restore their lead, with Jan Kopic grabbing what proved to be the winning goal for the Czech Republic champions.
Although Tuesday's hosts have won only one of their previous eight Champions League home games, they would be content with a draw that would help them progress to the next round.
While Plzen's domestic season begins this weekend, HJK Helsinki have six games left of their league campaign, with the defending champions currently three points behind league leaders KuPS.
Having played one game more than their title rivals, Toni Koskela's side face an uphill battle to retain the Veikkausliiga trophy.
Despite being in the midst of a title fight, HJK Helsinki will have to turn their focus to Champions League action on Tuesday as they bid to overturn a one-goal deficit.
Having won only one of their last six away Champions League games inside 90 minutes, HJK Helsinki will have to produce a faultless display to emerge victorious in the second leg.
If they can take the tie to penalties, the reigning champions of Finland will draw confidence from the penalty shoot-out victory they recorded against RFS in the previous round of Champions League qualifying.
Viktoria Plzen Champions League form:
HJK Helsinki Champions League form:
HJK Helsinki form (all competitions):
Team News
With no game to play between the two legs, Plzen are expected to name an unchanged side for Tuesday's contest.
Ludek Pernica will continue in central defence alongside Lukas Hejda, with the pair aiming to keep a clean sheet that would secure Plzen's passage into the next round.
After scoring in the first leg, Chory will provide one of the home side's main goal threats when he leads the line against HJK Helsinki.
As for the visitors, Renho and Raitala were rested at the weekend, with the duo set to return to the starting lineup to form a back three alongside Arttu Hoskonen.
David Browne was another player left out on Saturday, but the Papua New Guinea international is expected to start the second leg.
After scoring in the first leg, Radulovic found the net once again on Saturday, and the 22-year-old will be hoping to help his side overturn a one-goal deficit.
Viktoria Plzen possible starting lineup:
Stanek; Reznik, Pernica, Hejda, Havel; Bucha, Kalvach; Kopic, Sykora, Mosquera; Chory
HJK Helsinki possible starting lineup:
Hazard; Raitala, Hoskonen, Tenho; Browne, Hetemaj, Vaananen, Hostikka, Murilo; Abubakari, Radulovic
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