The hosts have been consistent top-six finishers in recent years, while their visitors have twice scraped clear of relegation since returning to the top flight in 2020.
Match preview
At he outset of a season in which several clubs can aspire to finish in the European positions, with Paris Saint-Germain again poised to sprint off into the distance, Rennes are seeking to emulate - or even surpass - last term's fourth-placed finish.
Bruno Genesio's side ended the 2021-22 campaign with more victories (20) and more points (66) than ever before, and their reward will be a return to the Europa League, following runs in the Champions League and Europa Conference League during the past two years.
As the path behind PSG is relatively open, Les Rouge et Noir will surely be aiming to qualify for the continent's top tournament this term, either through their league position or by going all the way in the Europa League, and they have been busy in the transfer market with that in mind.
Having lost West Ham-bound Nayef Aguerd and young striker Mathys Tel to Bayern Munich, Genesio has recruited Joe Rodon and Arthur Theate to bolster his back line. Veteran goalkeeper Steve Mandanda adds experience, too, after joining from Marseille.
After losing their opening pre-season fixture 1-0 away to Freiburg, Rennes secured successive wins against Caen, Augsburg and Derby de la Bretagne rivals Nantes to boost confidence in the camp.
Despite then suffering a home defeat to Aston Villa, in which Belgium defender Theate scored his first goal for the club, a largely successful summer programme sets them up for an opening-day game against a side they have dominated in recent times.
Losing four of their last five Ligue 1 matches against this week's opponents, Lorient are undoubtedly the junior partner in this meeting of Breton clubs.
Indeed, the visitors have conceded 20 times and failed to score throughout their nine most recent defeats to Rennes, and have let in at least one goal in each and every top-flight game played against them.
Such a start to the fixture list may not be welcomed, then, by former Rennes defender Regis Le Bris, who took the Lorient hotseat in June, after the departure of former coach Christophe Pelissier.
Naturally, after finishing 16th in each of the last two seasons, Les Merlus will justifiably be concerned about the league's forthcoming reduction to 18 teams, which means four clubs will be relegated next spring.
Lorient picked up a meagre 12 points on the road last term - the lowest tally in Ligue 1 - and ended with a run of just two points from their last five matches, so will start as outsiders in their season opener for 2022-23.
Rennes form (all competitions):
Lorient form (all competitions):
Team News
Though Rennes have seen defensive mainstay Nayef Aguerd depart for the Premier League this summer, they have since strengthened their rearguard options, and both Arthur Theate and Tottenham loanee Joe Rodon could start this weekend.
Steve Mandanda will take over in goal, while Matthis Abline returns from a successful loan spell at Le Harve to contend for a place up front.
Abline may have to make do with a place on the bench, as Martin Terrier (21 league goals in 2021-22) and Lovro Majer continue to link up in the final third, with Gaetan Laborde leading the line following 12 goals in 34 appearances last term.
Lorient, meanwhile, have seen German defender Moritz Jenz leave for Celtic and captain Fabien Lemoine - formerly of Rennes - depart the club after five years.
Swiss goalkeeper Yvon Mvogo has arrived from RB Leipzig, though, and Umut Bozok is back in the fold after being crowned the Super Lig's top scorer last season, while on loan at Kasimpasa. The latter, however, is soon expected to return to Turkey on a more permanent basis.
Having assessed his squad during pre-season, it remains to be seen how new coach Regis Le Bris sets the visitors up for his first competitive match in charge, but Nigeria striker Terem Moffi is set to be their focal point up front.
Rennes possible starting lineup:
Mandanda; Traore, Rodon, Theate, Truffert; Santamaria, Tait; Bourigeaud, Majer, Terrier; Laborde
Lorient possible starting lineup:
Mvogo; Igor, Laporte, Morel, Le Goff; Le Fee, Monconduit, Abergel; Loriente, Moffi, Ouattara