The eight-year-old is set to take his chance again in the £350,000 contest over an extended two and a half miles in this year's renewal.
Looking ahead to the Cheltenham Festival, trainer Paul Nicholls said: "Frodon did not have an ideal preparation before Christmas.
"He ran in the Old Roan under top weight in preparation for the Betfair Chase and they took all the fences out. He then completely under performed in the Betfair, about the only time he has run disappointingly for us, so Clifford [Baker] scoped him and found out he had grade four ulcers.
"It is odd because all the seasons he has been in training with us, he has never had an ulcer. But for whatever reason he had them, and grade four is as bad as it gets really. We got them cleared up and then tuned him up for Kempton.
"I thought he'd win and he did quite nicely. He has improved a lot since and worked very well with Clan des Obeaux this morning. He was his usual, free, enthusiastic self and gave Clan a good tow and kept on galloping.
"He loves this time of the year and is back where he wants to be. He is in the Magners Cheltenham Gold Cup but is almost certain to run in the Ryanair Chase again. He loves the New Course at Cheltenham and is ready to defend his crown. I think he will run very well again."
The Festival presented by Magners gets under way on March 10.