Leading LMP2 drivers Gustavo Menezes and Roman Rusinov have lost their silver-rated status in the revised list of FIA driver categorisations for next season.
Both Menezes and Rusinov are the designated silver-rated drivers in their respective teams, G-Drive Racing and Signatech Alpine.
FIA WEC rules state that all LMP2 crews are required to run at least one silver-rated driver in order to boost amateur participation.
There was controversy last winter as Rusinov, who took the LMP2 title in 2015 alongside Sam Bird and Julien Canal, was downgraded from gold status to silver, allowing him to fit in as G-Drive's amateur driver.
However, the Russian will now have to find a new silver-rated teammate in 2017, having been promoted back to gold.
Former F3 driver Menezes, who made his sportscar debut this season and won the Le Mans 24 Hours and LMP2 class title, will also no longer qualify as an amateur as a result of his 2016 success.
Among the other drivers being promoted from silver to gold are Rui Aguas and Ben Barker, both of whom race in WEC's GTE-Am division, as well as Le Mans 24 Hours GTE-Am class winner Jeff Segal.
Meanwhile, ESM's Ryan Dalziel has been demoted from platinum status to gold, while Antonio Giovinazzi, Billy Johnson, Richie Stanaway and Nicki Thiim have all been promoted from gold to platinum.