Denayer, who starred at Parkhead alongside Virgil Van Dijk, won PFA Scotland's Young Player of the Year award during his year on loan at Celtic from Manchester City.
The 30-year-old is still without a club.
Across 44 Celtic appearances during the 2014/15 season, Denayer scored six goals, winning a Scottish Premiership title and a Scottish League Cup.
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When he departed Al-Fateh last January, a statement read: "The club regrets saying goodbye to Jason Denayer. We would like to thank him for his excellent performance, commitment and professional mentality.
"Since his arrival at the club, Jason was one of the driving forces of our team and we would have preferred to keep him with us.
"However, due to his recent (minor) injury, he will not be able to play for about five weeks.
"Due to the current position of the club in the ranking, we cannot wait that long and are obliged to immediately recruit a replacement.
"The club does not legally have the option to field an additional foreign player and that is why we are very grateful to Jason for thinking along in the interests of our club.
"We wish this top defender all the best and hope to see him back at our club."