The teenager scored twice in four appearances for The O's, but has been recalled by Southend United.
Hooper's displays have prompted Orient boss Ling to hint at a bid to bring the youngster back to Brisbane Road.
"Gary did really well for us and I will continue to monitor his progress," Ling told the club's official website.
"I feel he did a good job during his time with the club."
Hooper was summoned back to Roots Hall to boost an injury-hit Southend squad ahead of Sunday's Championship finale at Southampton.
Shrimpers boss Steve Tilson explained: "We're light on numbers, so I decided to bring Gary back.
"He has trained with the squad and will be available for the trip to Southampton at the weekend."
