Mesut Ozil
Ozil is facing 12 weeks on the sidelines following a knee ligament injuryReuters

Arsenal boss Arsene Wenger has revealed that he let Mesut Ozil continue playing against Chelsea despite the German saying that he "felt a crack" in his knee during the game.

The former Real Madrid midfielder played for the full 90 minutes during the Gunners 2-0 defeat against Chelsea despite carrying an injury, and this eventually resulted in the German being sidelined for three months with a tear in his knee ligaments.

The full extent of the 24-year-old's injury was discovered when he teamed up with the German national team for their 2016 Euro qualifiers against Poland and the Republic of Ireland, with the German medical staff indicating that Ozil would be out for at least 12 weeks.

And now Wenger, who admits that he knew about the injury all along, says that he chose to risk Ozil because they were losing the game against Chelsea.

"He had a little problem just before he went out at halftime. He had a little pain with his knee, he felt a crack," Wenger told the Daily Mail.

"I said to our physio to keep an eye on him and if there was anything wrong with him, tell me because when you're 1-0 down, you want to keep your offensive players on the pitch."

However, the Frenchman says that he was not expecting the injury to be so serious considering he was not tackled or "involved in a collision" with anybody.

"I am deeply shocked. He wasn't involved in a collision with anybody," added Wenger.

"It was just after making a pass with the outside of his foot that he injured his leg so it's very hard to believe that you can damage your ligament with just making a simple pass and it's very difficult to take that he will be out for a while."

Despite injuries being a major problem for the Gunners season after season, Wenger refused to point a finger at his medical staff.

"I am not a great believer in coincidences, but this time it really is coincidence," added Wenger. "You cannot say our injuries are preparation mistakes. The big injuries we have are really accidental.

"Scientifically we are quite good. We have been hit hard after seven games. I would never have thought we would have had so many bad injuries."