Apprentice jockey Tom Sadler will have to pass a cognitive test before he can return to race riding after being concussed in a fall at Moonee Valley.

Sadler was lucky to escape more serious injury after coming off Massiyn who collapsed and died of an apparent heart attack leaving the straight in the final event on Saturday.

The young rider was taken to hospital for observation and released later in the evening.

Indentured to his trainer father John, Sadler will forgo his one ride at Kilmore on Tuesday and although booked for three mounts at Sale on Wednesday, he is not expected to ride until a day later at Warrnambool.

Sadler senior said his son was still feeling "sore and sorry for himself" and was given Monday morning off stable duties as he recovered from the fall.

"He's had a sleep in this morning and he can sleep for Australia," Sadler said.

"He'll have a couple of quiet days and then he'll be back into it."

"He's got a ride tomorrow but I doubt he'll be riding that, but he'll be back on Thursday for sure."

Sadler said he had looked at the video of the race and his son was lucky with the horse on his outside helping cushion the fall.

"It was fortunate that the horse on his outside cushioned him a little bit and broke his fall," Sadler said.

"I think that's where he's been able to come out of it OK and he also rolled pretty well."

Sadler said his son had some bruising just behind the rib cage after being kicked as the winner of the race, Schockemohle, went over the top of him.

An autopsy will be conducted on Massiyn.