Reigning King George VI Chase champion Best Mate will miss the Kempton race and run in Ireland instead on Sunday.
Trainer Henrietta Knight made the surprise decision after assessing the ground at the English track.
The dual Cheltenham Gold Cup winner will now contest the Ericsson Chase at Leopardstown.
Knight said: "I think it might be too quick for him at Kempton and at the end of it all, it is the best interests of the horse we have at heart.
"It wasn't the opposition that made us change our mind - it was very much the weather.
"We are trying to get him ready for a third Gold Cup win in March and we have to get the horse there in the best possible condition to defend that title."
The switch means Best Mate misses a rematch on Boxing Day with Jair du Cochet, who defeated the Gold Cup hero at Huntingdon last time out.
 | Best Mate is in very good shape  |
Jair du Cochet is now clear favourite for the King George, with fellow French chaser First Gold among the challengers.
Hennessy Cognac Gold Cup winner Strong Flow could be another challenger, although he is also entered in the Feltham Novices' Chase at the same course.
Best Mate's switch sets up a mouthwatering contest in Ireland, where Knight's horse will take on a top-quality field, including Gold Cup contenders Beef or Salmon and Keen Leader.