"I will leave in January," the Egyptian defender told FilGoal.com in a phone call from France.
"I can't stay any longer (without playing)."
The international left-back featured only three times this season and was left out of his side's squad in the past seven games.
Abou-Mosallam has yet to know his next destination but said he will consider offers before deciding in January.
He didn't rule out staying with the Ligue 1 club should changes happen in the coaching staff before the New Year.
"I may stay only if manager Jean-Marc Furlan left before January," Abou-Mosallam said.
Strasbourg are tenth in the league on 23 points, with two games to go in the first half of the season.
Abou-Mosallam told FilGoal.com in August: "I've been overlooked since he took over as coach."
"He signed a 34-year-old French full back, whose knee injury kept him on the sidelines for a year. Yet, he prefers to start him."
The former Ahli player moved to Strasbourg two years ago and played a pivotal role in the club's promotion to the French top flight.