Declan Rice urged that Arsenal weren't clinical enough in the final third as his side were beaten 2-1 by Lens on Tuesday night.
The Gunners took the lead in the Champions League clash through Gabriel Jesus but were unable to capitalise on their advantage, with the French club coming from behind to win thanks to goals from Adrien Thomasson and Elye Wahi.
Thomasson's well-taken equaliser in the 25th minute came after Arsenal's No 1 goalkeeper David Raya gave the ball away poorly playing out from the back.
Kai Havertz, Gabriel Jesus, Leandro Trossard and Takehiro Tomiyasu were among those who squandered great opportunities before Wahi's second-half winner for Lens, while substitute Reiss Nelson missed a superb chance to level the score in the closing stages.