Honda rider Michael van der Mark and Yamaha's Alex Lowes both require medical evaluation after pulling out of the World Superbike post-season test at Jerez.
Lowes, who joined Yamaha from Suzuki, dislocated his shoulder in a crash on Wednesday and had to fly back to the UK to seek specialist treatment.
"I felt really good on the bike yesterday and was able to be fast and consistent," Lowes commented. "I just made a small mistake, and perhaps got caught out by the drop in temperature at the end of the day, and it resulted in a pretty big crash!"
Van der Mark also bowed out after Wednesday, his team citing right arm pain as the reason, with the Dutchman now also requiring treatment.
The five-day Jerez test will conclude without them with runs on Thursday and Friday.
Reigning champion Jonathan Rea has thus far set the best time of the test, with a 1m40.139s on Tuesday.