Martin Pipe's star chaser Well Chief has been sidelined for the rest of the season due to injury.
Well Chief was second to Azertyuiop at Cheltenham in March
The six-year-old was found to have some heat in his leg and will miss the new campaign.
His last run was a four-length win over Azertyuiop in the Betfred Celebration Chase at Sandown in April.
The 2005 Champion Chase runner-up has won eight of his 19 starts to date, including beating Kicking King in the Arkle Chase at the Cheltenham Festival.
"A scan has revealed a slight change from normal," said a statement on Pipe's website.
"Chiefy is not lame but he is far too good to risk and on veterinary advice, a long rest is to been taken.
"This news is very disappointing for his owner David Johnson and everybody at Pond House, but he is only six and he will be back next year as a seven-year-old."
Azertyuiop is also out for the season after he suffered an injury in his Sandown defeat to Well Chief.