Wolfsburg defender Sotirios Kyrgiakos has apologised for the clash with Neven Subotic which led to the Borussia Dortmund defender needing facial surgery on Saturday night. Subotic had three metal plates inserted in his face in an operation at a Bochum clinic after being caught by Kyrgiakos\' elbow during an aerial challenge. Subotic will miss up to six weeks due to the multiple fractures. \"I am deeply saddened by the serious injury,\" Krygiakos is quoted as saying by the Bild newspaper. \"It was an accident. I did not see him as I was running backwards and I wanted to leap for the ball. I hope that he gets back onto the field as soon as possible.\" The clash happened in the 42nd minute and, although Subotic carried on, it was soon clear when the teams entered the dressing room at the interval that the Serbia international needed help. \"Neven\'s face swelled up brutally in a matter of seconds,\" reported Dortmund coach Jurgen Klopp. \"It looked truly awful.\"