A total of 37 cars will line up for the final round of the 2016 European Le Mans Series at Estoril later this month.
The number is two lower than the penultimate round at Spa, with three LMP2 teams dropping out ahead of the Portuguese race.
Algarve Pro Racing nearly finished on the podium at Spa but has decided to cancel its plans to race on home soil in favour of the Asian Le Mans Series opener at Zhuhai.
Meanwhile, Team WRT’s toe-in-the-water entry with a Judd powered Ligier last time out was a one-off and it will not travel to Portugal, as expected.
Irish squad Murphy Prototypes’s ORECA 03 will also be absent, reducing the field to just two open cockpit LMP2 cars.
The 4 Hours of Estoril marks the final race for open-top prototypes in top level sportscar competition, before they are outlawed in 2017.
At the head of the field there are no changes, with Thiriet by TDS Racing, G-Drive Racing and SMP Racing all ready to battle for the overall championship.
Additionally, Pegasus Racing has replaced Remy Streibig with Julien Schell in its Morgan-Nissan.
In LMP3, the grid gets boosted up to 19 with the return of the two-car entry from Eurointernational.
The Italian outfit missed out on racing at Spa, but is back with a revised lineup that includes Jay Palmer, who raced in the Prototype Cup curtain raiser last weekend.
Absent from the LMP3 entry list is Tockwith Motorsport, which has traveled to China for the opening round of the Asian Le Mans Series with its Ligier JSP3.
All eight LMGTE entries from the 4 Hours of Spa are carried over to Estoril, with only one driver change to note in the class.
Proton Competition has switched its lineup a few times this season, and will welcome another new driver next weekend as World Endurance Championship racer Ben Barker joins the team.
Barker, who campaigns a Gulf Racing Porsche 911 on the world stage, will share the Proton-run 911 with Christian Ried and Gianluca Roda.
The British driver replaces Matteo Cairoli, who will be attempting to secure the Porsche Supercup title at Circuit of the Americas on the same weekend.
The final round of the 2016 European Le Mans Series will get underway at 13:30 local time on Sunday, October 23.