Magnussen and De Vries were set to start 19th and 20th on the grid respectively, so both their teams elected to breach parc ferme rules and make changes to the cars with a minimal penalty.
In Magnussen's case, Haas opted to tweak the set-up of his VF-23 car.
De Vries' changes are much bigger in scope, with AlphaTauri changing the Dutchman's rear wing and beam wing to a previous specification after he struggled for straight-line speed in Saturday's sprint. They also include a set-up change to the suspension of his AT04.
AlphaTauri has also used the opportunity to install a new energy store and set of control electronics from Honda.
As it is De Vries' third set of each power unit component for 2023, with only two examples allowed for the whole season, that would have netted him a grid penalty, but that has now been absorbed by the pitlane start.
AlphaTauri had brought a new rear wing and beam wing to the Red Bull Ring in a bid to improve efficiency for the Spielberg round.
In Friday's qualifying, fine margins at the 4.318km circuit cost Magnussen dearly in Q1 as he was dumped out in 19th while team-mate Nico Hulkenberg advanced to Q3.
The Dane did qualify 10th for Saturday's sprint, but then dropped back on a drying track to finish 14th, saying he "didn’t really have great pace on either the intermediates or the dry tires."
Under pressure De Vries similarly struggled to make an impact, finishing 17th in the sprint after a prolonged battle with Williams' Logan Sargeant.
"I think the slicks performance was fine, but we were just locked behind Logan," said De Vries.
"They have a kind of different compromise than us and their straight-line performance is very strong, and then racing becomes challenging."
