Vladimir Coufal has started the season in superb form, with four assists already to his name in the Premier League, but has not made the trip to Athens, where David Moyes's men are looking to extend their 17-match unbeaten run in Europe.
"He was just a bit tight so I left him at home," Hammers boss Moyes explained, suggesting Coufal's problem is minor, though he gave no indication as to whether the Czech international would be fit to face Everton in the top-flight on Sunday.
Thilo Kehrer starts at right-back in Coufal's place, but Moyes's defensive options have been bolstered by the returns to fitness of Ben Johnson and Aaron Cresswell, both of whom have travelled to Greece and are on the bench.
"I think Johnson's a bit further ahead of Cressy at the moment but if required they're both ready to play," Moyes confirmed.
Elsewhere, summer signing Konstantinos Mavropanos starts at centre-back on his return to his homeland after taking on media duties on Wednesday night, while Alphonse Areola starts in goal with Lukasz Fabianski ill.
Moyes has shuffled his pack, with Jarrod Bowen, Lucas Paqueta and Kurt Zouma among those to drop to the bench, as Danny Ings leads the line and Mohammed Kudus gets another chance to impress in Europe.
West Ham XI: Areola, Kehrer, Mavropanos, Ogbonna, Emerson, Ward-Prowse, Soucek, Benrahma, Kudus, Fornals, Ings
Subs: Anang, Cresswell, Johnson, Zouma, Aguerd, Alvarez, Cornet, Paqueta, Bowen, Antonio, Mubama
Date and time: 5.45pm BST, Thursday October 26, 2023
Venue: Georgios Karaiskakis Stadium