Dual Grand National runner-up Suny Bay's future will be decided this week.
The 11-year-old, pulled up in the Hennessy Cognac Gold Cup on his only start to date this season, is to undergo a thorough veterinary examination.
Trainer Simon Sherwood said today that if the test do not give the chaser a clean bill of health, then Suny Bay will be retired.
Sherwood said: "He has got a crooked back and with that a knee or an ankle, or something else goes.
"His problem is his off-hind joint, hence the spring in his jump has rather gone. The flamboyance in his jumping has gone.
"The flat work is brilliant but he doesn't know quite how to get from one side of the fence to the other.
"We have given him plenty of time to see if the problem will subside or not. Now we'll do a Gamma scan to see if there are any heat spots still in that area.
"If it's gone then well crack on, but if there's a problem well put our heads together and make whatever decision needs to be made.
"It's a question of whether we have a racehorse still to go on or whether he'll retire. He hasn't got much mileage on the clock and he's been a wonderful servant but he isn't the perfect physical item."
Suny Bay won the 1997 Hennessy at Newbury and was second in the Grand National in both 1997 and 1998.
