Auer lost control of his #57 Winward Racing Mercedes-AMG GT3 coming out of Turn 1, just moments after setting the fastest time in the GT Daytona class, before smashing head-on into the concrete wall near Turn 2 that separates the pit exit from the race track.
The accident triggered a red flag interruption of about 20 minutes, in which time Auer was retrieved from the stricken car. According to observations by photographers, the rollcage was cut open during this process.
Auer was transported to hospital, and was reported to be conscious but complaining of back pain.
Significant damage to the Winward Mercedes means a replacement chassis is likely to be needed for the team to take part in the 24-hour event this weekend. The team sat out second practice, with few efforts being made to repair the car prior to the session.
Winward has yet to issue an official statement on the matter.
Auer's team-mate Philip Ellis put the #57 car on pole position in the GTD class in last weekend's qualifying session, also outpacing the best of the GTD Pro cars, leading an all-Mercedes top four.
The AMG-GT3 shared by Auer, Ellis, Russell Ward and Indy Dontje outpaced the SunEnergy1 Racing example of Kenny Habul, Luca Stolz, Axcil Jefferies and Fabian Schiller.
WeatherTech Racing claimed pole in GTD Pro with its Mercedes shared by Dani Juncadella, Jules Gounon, Maro Engel and Cooper MacNeil, and was fourth in the overall GTD order behind the #32 Team Korthoff Motorsports car.
Source: Autosport