The Ligue 1 outfit qualified for Europe's elite competition owing to their third-placed finish in the 2019-20 French top-flight campaign, whereas Krasnodar overcame PAOK in the playoff round to secure a route into the group stage.
While Sevilla and Chelsea will ultimately be the favourites to progress to the knockout rounds of this season's elite competition, Rennes will head into their first-ever Champions League venture knowing that they have little to lose when they face off against the big boys.
Had Julien Stephan's men taken to the pitch on the international stage before the Nations League fixtures took place, the Rennes faithful may have been feeling more confident about a positive result following two underwhelming performances in Ligue 1 over the past couple of weeks.
Indeed, Rennes have only taken two points from a possible six against two struggling sides in Reims and Dijon - both of whom currently occupy spots in the relegation zone - with Martin Terrier's opener for Les Rouge et Noir cancelled out by Dijon's Mama Balde in gameweek seven of the 2020-21 Ligue 1 campaign.
Nevertheless, Stephan is yet to witness his side fall to defeat in the current league season and Rennes only sit behind perennial champions Paris Saint-Germain on goal difference at this early stage, and Rennes' focus now turns to a Krasnodar outfit who have endured a mixed start to domestic proceedings.
Krasnodar prepared for their trip to the Roazhon Park with a comfortable 3-1 league triumph over Rubin Kazan on Saturday, but their start to the season has not gone as smoothly as Murad Musaev would have hoped.
While the Bulls have notched up an impressive 21 goals this season - a feat which is only bettered by table-toppers Zenit Saint Petersburg - Krasnodar sit sixth in the table and have already lost half the amount of games as they did in the whole of last season.
Krasnodar have been put to the sword by Lokomotiv Moscow, Ural and Dinamo Moscow so far, but their loss to the latter is the only defeat that Musaev's men have suffered in their last nine outings in all competitions, and the Russian top-flight side overcame Greek outfit PAOK 4-2 on aggregate to qualify for the Champions League group stage for the first time ever.
Having plied their trade in the Europa League for five out of the last six seasons, Krasnodar supporters will be hoping that their side's strong recent results in the Russian Premier League can translate into valiant performances against Europe's top teams over the coming months.
Rennes form (all competitions): WWWWDD
Krasnodar Champions League form: WW
Krasnodar form (all competitions): WWDWLW
Teenage protege Eduardo Camavinga is expected to come back into the starting lineup for Rennes after his international exploits with France - the 17-year-old only made the bench for Les Rouge et Noir's 1-1 stalemate with Dijon.
Camavinga's reintroduction is likely to see Flavien Tait demoted to the bench, while Jeremy Doku will look to get some more minutes on the board after making his debut as a substitute for Stephan's side on Friday.
Damien Da Silva and Steven Nzonzi both missed out at the weekend due to suspension but the pair are in line for recalls to the side here, while new arrival Alfred Gomis could replace the veteran Romain Salin in goal after returning to training from a thigh injury.
Sweden stalwart Marcus Berg came off the bench to bag Krasnodar's third in injury time against Rubin Kazan and will be holding out for a start on Tuesday.
Rennes possible starting lineup:
Gomis; Traore, Da Silva, Aguerd, Dalbert; Nzonzi, Camavinga, Bourigeaud; Doku, Guirassy, Terrier
Krasnodar possible starting lineup:
Safonov; Petrov, Kaio, Sorokin, Ramirez; Vilhena, Gazinskiy; Suleymanov, Cabella, Claesson; Berg
We say: Rennes 2-1 Krasnodar
Rennes will be determined to make amends following two lowly draws in Ligue 1 by marking their first-ever Champions League appearance with a vital three points. Tuesday's showdown is poised to be a hotly-contested battle between two sides who have been solid overall in the past few weeks, and while Krasnodar will feel capable of making the long journey back to Russia with something to show for it, we think Rennes will do enough to come out on top.