The France striker clashed heads with James Tomkins 16 minutes from time at the Emirates Stadium, sparking fears of having sustained a serious injury as he lay motionless on his back before team-mate Nacho Monreal and a cluster of players helped to roll him on to his side.
Both Giroud and Tomkins eventually got back to their feet after receiving lengthy treatment and finished the match, though neither were assessed by an independent doctor in the tunnel - a Premier League requirement for dealing with incidents of concussion.
Arsenal were widely criticised for keeping Giroud on the pitch as they chased the game - which ended 2-0 to West Ham courtesy of goals from Cheikhou Kouyate and Mauro Zarate - but took to Twitter to dismiss any suggestion that the Frenchman was concussed.
The Gunners' official account tweeted: "Update on Olivier Giroud: contrary to some reports, he was not unconscious at any point after collision today and has returned home as usual."
