McLaren Formula 1 drivers Fernando Alonso and Stoffel Vandoorne are set to start this weekend's Mexican Grand Prix from the back of the field after the FIA stewards c🐭onfirmed their grid penalties followi𓃲ng power unit changes ahead of practice on Friday.

Alonso and Vandoorne confirmed on Thursday they would be making a number of changes to their Honda powerꦿ units ahead of the race weekend, expecting to receive hefty grid drops as a result in the latest setback for McLaren in a🅰 tough season.

The penalties were confirmed by the FIA race stewards at the Autodromo Hermanos Rodriguez 🐟during FP1 on Friday, with Alonso dropping 20 places on the grid after taking a new internal combustion engine, turbo and MGU-H. Vandoorne wꦗill drop 35 places after taking a complete new power unit.

"The circuit is not the perfect for our package anyway ,so we don’t expecꩵt to be super-competitive here," Alonso said on Thursday.

"Maybe it is the best place for the penalty and hopefully we can be bett𓃲er in Brazil and Abu Dhabi wi🀅th the new engine."

Vandoorne added: "Hopefully it should be the last grid penalty [this s🐲eason] but we knew this would be aও difficult circuit for us in terms of performance.

"We were always planning to take a penalty here, to protect us for the last two race🍒s, where hopefully✤ we should be more competitive and have more opportunities."