The England winger was forced off for the third time in as many games against Lens in France on Tuesday as Mikel Arteta’s decision to start him ahead of Sunday’s key Premier League showdown with title rivals Manchester City backfired badly.
Playing for an hour without their chief attacking threat, below-par Arsenal were passive and ponderous as they slipped to a shock 2-1 defeat - their first in any competition so far this season - in Group B at a bouncing Stade Bollaert-Delelis, hosting Champions League football for the first time in two decades.
Record signing from Montpellier Elye Wahi - linked with Arsenal, Chelsea and West Ham over the summer - popped up with a stylish winning goal for Lens 20 minutes from time on a famous evening for Franck Haise’s side, who finished as runners-up to Paris Saint-Germain in Ligue 1 last season but had made a wretched start to the new campaign and hover just above the relegation zone.
Gabriel Jesus had earlier ruthlessly fired Arsenal into a 14th-minute lead after Saka seized on an errant pass from Adrien Thomasson, who quickly atoned for his error with a wonderful finish just 11 minutes later after great play from Wahi that followed Arsenal losing possession cheaply out wide thanks to a poor David Raya kick towards Takehiro Tomiyasu.
Arsenal created preciously little apart from Jesus’ goal as they failed to take early control of Group B and suffered a hit to both form and confidence before they try to take down City in north London on Sunday, with an anxious wait ahead over Saka’s fitness for that potentially pivotal match.