Jockey Josh Moore is in critical care at Aintree University Hospital after complications from a chest infection.
The rider suffered multiple injuries when parting company with Gleno at the sixth fence in the Rising Sun Veterans' Handicap Chase.
Moore has since undergone a successful operation on his broken femur, but remains under sedation as a chest infection is stalling his treatment.
The Injured Jockeys Fund provided an update on Moore on Wednesday, which read: "Following his fall at Haydock on Saturday, jockey Josh Moore is in critical care at Aintree University Hospital.
"After successful surgery to his femur, his recovery has been made complicated by a serious chest infection which has required him to stay sedated on the ventilator and has delayed definitive treatment of his injuries.
"The specialist medical team are working hard to treat Josh, and his family remain by his bedside."
The sportsman was hurt when Gleno collided with him when he came down at Haydock on Saturday.
Trained by his father Gary Moore, the chaser was tracking the leaders when he parted company with his rider.
Medics assisted Moore, who went in an ambulance to Aintree Hospital, where scans revealed he had broken his leg, several ribs, punctured a lung and damaged his lower back.
He spent several months on the sidelines earlier this season after another fall led to spinal surgery.
His sister Hayley Moore told Sky Sports Racing on Monday: "He's had the operation on his leg and there are no complications and they are happy with it. We're just waiting for him to come round."
It is the latest injury setback for talented jockey Moore, who recorded his best season to date in 2020-21 with 40 winners.
