Lindsay Charnock will be sidelined for at least another two months following an operation to remove a blood clot in his groin.
Charnock has undergone two operations to repair blockages in the groin and his pelvis area and had planned to start riding at the beginning of next week.
He has been out of action since early January and his wife Gloria explained today: "He rode out for Tim Easterby on Tuesday and came back home and said he felt absolutely fine with no twinges or anything.
"He then went for a work out on Kevin Darley's mechanical horse but he felt there was a problem again and his foot went numb.
"He quickly arranged an appointment at a hospital and a scan revealed that a blood clot had formed in the area of the groin where the problem first surfaced.
"He had an operation last night to remove it and he will have to stay in for a week. The surgeon has told him he must not do anything at all for eight weeks, not even sit on a horse.
"He said that if it got to the stage where they had to insert a plastic vein he would not be able to ride because it would keep breaking so he has got to give this every chance to heal properly.
"He is not happy at all as you can understand, and the most frustrating thing for him is that he thought he was all set to make a comeback.
"Now the season will be three or four months old before he gets back."