Gabriel is missing from the Arsenal squad that faces Manchester United in the Premier League on Wednesday night. The defender was in a race to be fit after withdrawing from the clash with West Ham at half-time over the weekend.
Gabriel told fans on Instagram "see you Wednesday" in an apparent suggestion that he would be ready to play. But the Gunners will have to do without their centre-back, who has scored in his last two matches.
The Brazilian has been instrumental in Arsenal's deadly set-pieces this term, notching four goals.
Full-back Riccardo Calafiori is also missing from the squad through injury, meaning Jurrien Timber and Oleksandr Zinchenko come into the back four.
Meanwhile, United dropped winger Amad to the bench, despite the 22-year-old starring in the 4-0 romp against Everton on Sunday.
Mason Mount makes his first start for Ruben Amorim, while Harry Maguire is deemed fit to play from the start and Rasmus Hojlund returns up top.
Arsenal starting XI; Raya, Timber, Saliba, Kiwior, Zinchenko, Odegaard, Partey, Rice, Saka, Havertz, Martinelli
**Subs:**Neto, Tierney, Heaven, Jorginho, Merino, Sterling, Nwaneri, Trossard, Jesus
Man Utd starting XI; Onana; Maguire, De Ligt, Mazraoui; Dalot, Ugarte, Fernandes, Malacia; Garnacho, Mount; Hojlund
Subs: Bayindir, Kukonki, Yoro, Casemiro, Eriksen, Amad, Antony, Rashford, Zirkzee