VIKTOR GYOKERES was left with a nasty head wound after a collision with an Arsenal team-mate in their Champions League clash against Athletic BilbaoThe Swede was on the receiving end of a clash of heads with Gabriel when the pair both jumped for the same ball during an attacking free-kick.Viktor Gyokeres was left with a gruesome injury after a clash of heads with GabrielThe Swede was seen with bleeding from the back of his head after both went up for the ball at a free-kickThe incident happened in the 30th minute, and left both Gyokeres and Gabriel down on the turf.However, Gyokeres had his hand placed on the back of his head before medical staff rushed over to treat the gash.TNT Sports cameras picked up Gunners boss Mikel Arteta grimacing as his star forward fell to the floor.The 27-year-old remained on his knees and head on the grass before he was fashioned with a black headband – reminiscent of former England star Terry Butcher. As part of the procedure with head injuries, Gyokeres had to temporarily leave the pitch.He was eventually allowed to return four minutes later.Gyokeres has hit the ground running in the Premier League following his transfer from Sporting Lisbon in the summer. The ace has scored three goals – two against Leeds and one last weekend against Nottingham Forest – in four games since his £63million move to the Emirates.THIS IS A DEVELOPING STORY..The Sun is your go to destination for the best football, boxing and MMA news, real-life stories, jaw-dropping pictures and must-see video.Like us on Facebook at https://www.facebook.com/TheSunFootball and follow us from our main Twitter account at @TheSunFootball.