The hosts are playing in the competition for the fifth time, having last made it to this stage in 2018-19, with the visitors embarking on their first-ever campaign in Europe's elite competition.
Match preview
Ljubljana may have reached the Champions League qualifiers on five previous occasions, but they have never made it past the second qualifying round, and they will be looking to go further into the competition this time around.
The Green and Whites were only founded 18 years ago, but they have started to become a real force in recent years, winning three league titles and four Slovenian Cups, managing to do the double last season.
Joao Henriques has recently replaced Albert Riera as manager of the Slovenian champions, and he is tasked with following up a fantastic campaign, in which they amassed 73 points in 36 league games, winning the title by a six-point margin.
That said, Ljubljana did lose their last three matches of the league season, most recently falling to a 2-0 defeat at home against Celje, despite dominating the majority of the possession throughout the match.
Since then, however, Henriques' side have gone on to win five of their six friendly matches, defeating Rudar in comprehensive fashion last time out, romping home to a 4-0 victory.
Valmiera won the Latvian Higher League for the first time in their history in 2022, and after a long wait, they are finally embarking on their maiden Champions League campaign.
However, Jurgis Kalns's side are currently third in their ongoing league, 18 points behind second-placed Rigas Futbola Skola, so there may be some understandable trepidation heading into a tournament featuring some of Europe's elite sides.
The Latvian league runs from March to November, so Tuesday's visitors are not short of match practice, but they have not been in the best of form, winning just two of their last seven matches.
Most recently, however, Valmiera ran out 6-0 winners against Tukums 2000, with Gustavo Silva bagging a brace, which should give them some confidence heading into Tuesday's game.
NK Olimpija Ljubljana form (all competitions):
Valmiera form (all competitions):
Team News
Svit Seslar played a vital role for Ljubljana en-route to the league title last season, weighing in with nine goals and four assists in the league, and the 21-year-old is set to feature in an advanced midfield role.
The youngster is likely to be playing provider for Mustafa Nukic in attack, given the Slovenian's fine form in pre-season, scoring a brace against Rudar last time out, and he could be joined by Rui Pedro.
After his side ran out 6-0 winners in their last match, Kalns is unlikely to make any changes to his Valmiera side, with Ruan Ribeiro set to lead the line in what is likely to be a 4-1-4-1 system.
Having both found the back of the net on Friday, Alioune Ndoye and Gustavo Silva are set to continue in central midfield, with Kristers Cudars playing in a deeper role, taking on more defensive responsibilities.
NK Olimpija Ljubljana possible starting lineup:
Vidovsek; Lasickas, Muhamedbegovic, Krefl, Posavec; Doffo, Elsnik, Fatnik, Seslar; Nukic, Pedro
Valmiera possible starting lineup:
Olses; Jaunzems, Veips, Balodis, Fall; Cudars, Tonisevs, Ndoye, Silva, Mena; Rodrigues
We say: NK Olimpija Ljubljana 2-0 Valmiera
NK Olimpija Ljubljana have much more experience in the Champions League, while they also come into the game fresh off the back of a fantastic title-winning season and some solid performances in friendly matches.
As such, we expect the Slovenian side to record a comfortable victory against a Valmiera side who are currently struggling in their domestic league.