In the past season, the reserve seat for Mercedes was occupied by Esteban Ocon who signed a contract with the Renault for the 2020 season.
Stoffel Vandoorne is the Formula E championship leader and he has been replaced by Lando Norris who took his seat in McLaren at the end of 2018.
In the coming season he will be the reserve driver together with his ex team mate, Esteban Gutierrez and they will share the reserve seat.
Super happy to be part of @mercedesamgf1 as their Reserve Driver this season. 🎉— Stoffel Vandoorne (@svandoorne) February 14, 2020
Let's get to business here at the #MexicoCityEPrix and defend that lead in the championship. 👊#wedrivethecity #ABBFormulaE #drivenbyEQ pic.twitter.com/DV2CcuZQDw
This re-entry will probably causes some issues for the Belgian driver considering that he will also be involved in the FE calendar.
In fact the Rome E-Prix coincides with the Vietnamese GP, the Seoul E-Prix matches the Dutch GP and the Baku F1 race weekend will correspond to the Jakarta E-Prix.