However, with the team finishing 2020 strongly, and with Scott McLaughlin departing for IndyCar, there's little doubt both Red Bull Ampol have a solid chance to be series champion by year's end.
Both drivers had mixed campaigns last year; Whincup will be determined to claim an eighth title after his 2020 chances faded late, while van Gisbergen won four of the last eight races.
Dick Johnson Racing: Will Davison vs Anton De Pasquale
The team at the head of the pit lane will feature an all-new line-up, which consists of two vastly different drivers.
DJR has championship-winning machinery on its side, and two proven winners behind the wheel.
Will Davison returns to DJR, having left the team at the end of 2008. Back then, Anton De Pasquale was only 13 years old. Davison has flourished to become a two-time Bathurst winner, but has bounced from team to team, including the Holden and Ford factory teams.
De Pasquale was an open wheel ace, but at 25, has more than enough to time to carve out a brilliant Supercars career.
Tickford Racing: Jack Le Brocq vs Cameron Waters vs James Courtney
Kelly Grove Racing: Andre Heimgartner vs David Reynolds
One of the most intriguing line-ups in 2021 will be the rejigged Kelly Grove Racing squad, with former Bathurst winner David Reynolds linking up with Andre Heimgartner.
Heimgartner lines up for his fourth season with the Kelly squad, while Reynolds returns to the team he left in 2011.
Chaz Mostert had Bryce Fullwood's measure at Walkinshaw Andretti United, and both are eyeing improved campaigns in 2021.
Matt Stone Racing's two young guns, Jake Kostecki and Zane Goddard, will be pitted against each other in full-time seasons following part-time SuperLite campaigns in 2020.
Nick Percat is expected to lead the Brad Jones Racing charge, although Todd Hazelwood will be looking to add to his maiden pole and podium last year.
Team Sydney, meanwhile, enters 2021 with an all-new line-up, with a motivated Fabian Coulthard joined by Garry Jacobson.