Viktor Gyokeres required treatment for nearly four minutes after sustaining a cut to his head during Arsenal's opening Champions League match with Athletic Club.
The Arsenal forward clashed heads with his team-mate Gabriel Magalhaes as the pair attempted to attack a free kick into the Athletic Club box.
Gyokeres and Gabriel both fell to the turf following the incident in the 30th minute of the match at the San Mames Stadium, with the former coming off worse in the collision.
Medical staff were required to attend to Gyokeres, with footage showing that the forward had sustained a gash to the back of his head.
The Swedish forward was seen bleeding as he received treatment for the wound.
Gyokeres was eventually patched up by Arsenal's medical staff, with the £64million summer signing sporting a black headband as he returned to the action.
The match was able to resume following a four minute delay to proceedings.
