Lens secured a return to the top level courtesy of finishing second in Ligue 2 last term, while Nice claimed fifth in Ligue 1, although neither side were able to finish their respective campaigns due to the coronavirus outbreak.
Eleven wins, eight draws and nine defeats - that is how Nice performed during their 2019-20 Ligue 1 campaign, with a total of 41 points from 28 matches ultimately seeing them finish fifth in the table.
Patrick Vieira's side were eight points off fourth-placed Lille when the season was called to a halt in March and actually only one point above ninth-placed Monaco.
Les Aiglons had been in good form in the early stages of 2020, though, and picked up eight points from their four Ligue 1 matches immediately before the coronavirus-enforced shutdown.
France decided to end their campaign prematurely, but Nice have been preparing for the 2020-21 season since the start of July, playing friendlies against Lyon, Saint-Etienne, Celtic, Rangers, Standard Liege, DAC, RB Salzburg and Rennes, picking up three wins from their last four matches.
Lens, meanwhile, were second in Ligue 2 when the season was called to a halt, meaning that they were automatically promoted back to the top tier alongside league leaders Lorient.
A successful 2019-20 campaign saw Franck Haise's side win 15 of their 28 matches, drawing eight and suffering just five defeats, and they are back in the top tier for the first time since 2014-15.
Indeed, Lens have spent the last five years in Ligue 2, which is incredibly for a side that won Ligue 1 in 1997-98 and has also finished as runners-up in the top tier on four separate occasions.
The visitors have won three of their six pre-season matches this summer and will be determined to open their campaign with a positive result, although they lost 2-1 on their last visit to Nice in May 2015.
Nice pre-season form: DLWWLW
Lens pre-season form: DWWLLW
Morgan Schneiderlin has also joined from Everton, and it would not be a surprise to see the experienced midfielder handed a spot in the XI on Sunday afternoon.
Kasper Dolberg scored 11 times in 26 outings for Nice last season following his arrival from Ajax, meanwhile, and the 22-year-old is likely to lead the line for the home side.
There will be changes from their last competitive match against Monaco, though, as Malang Sarr and Arnaud Lusamba have left the club on free transfers, while Adam Ounas, Riza Durmisi and Moussa Wague have all returned to their parent clubs following loan spells.
Lens, meanwhile, are expected to have former Chelsea youngster Gael Kakuta in their starting XI, with the attacker arriving on loan from Amiens for the 2020-21 campaign.
Fofana and Kakuta are likely to go straight into the starting side, but there is expected to be a similar look to the team that featured against Orleans in their last Ligue 2 match on March 9.
Nice possible starting lineup:
Benitez; Dante, Danilo, Bambu; N'Soki, Maurice, Lees Melou, Schneiderlin, Burner; Dolberg, Maolida
Lens possible starting lineup:
Leca; Fortes, Diallo, Radovanovic; Boli, Doucoure, Fofana, Michelin; Sotoca, Kakuta, Jean
We say: Nice 2-0 Lens
Lens will fancy their chances of causing some problems this weekend, but it is a tough ask to overcome Nice in their first game back at this level of football. We are expecting the hosts to emerge victorious, with Danish striker Dolberg potentially making the difference in the final third of the field.