Raul Jimenez received treatment from medics for 10 minutes on the pitch after colliding with David Luiz before being stretchered from the field early on in the game.
Willian was pictured on Instagram at the Nusr-Et steakhouse in Dubai with celebrity owner Nusret Gokce, more commonly known as "Salt Bae".
Despite Gareth Bale starting for the first time, it was on-loan Carlos Vinicius who made an impressive debut as Tottenham enjoyed a 3-0 win in their Group J opener.
David Luiz had joined Arsenal from Chelsea last year on a one-year deal.
Sheff Utd vs Arsenal: Arsenal sit fifth in the Premier League table after a powder-puff performance that showed Unai Emery's rebuilding job is still a work in progress.
Arsenal vs Bournemouth: Arsenal edged up to third in the Premier League as David Luiz's first goal for the club earned a 1-0 win over Bournemouth.
Virat Kohli got a message of good luck from Brazil and Chelsea star David Luiz.
Centre-back David Luiz has been a mainstay in Maurizio Sarri's Chelsea this season.
Chelsea's opening seven Premier League games have yielded five wins and two draws
Courtois, 26, has a year remaining on his contract and has been repeatedly linked with a move to Real Madrid