Dejagah said that he is feeling good and believes that he could return to action in "five or six weeks".
"I feel good," he told the club's official website. "It has been nine weeks since my operation and I have started running. I am looking forward to starting training again soon and I have five or six weeks to work with the physios to get me in the best possible shape for pre-season games and the start of the Premier League.
"It was a big blow. It was the first time that I have suffered a big injury like that and it was frustrating as I was playing well. It would have been great to finish the season and help the team, but this is football and hopefully I can come back even stronger.
"I hope that I am ready for the first game and have enough time to work with the team before the start of the season. I look forward to playing a part in pre-season so I can be as fit as possible."
Dejagah was injured on April 1 and underwent surgery towards the end of last season.