It had been claimed that the seven-year-old was coughing, but Henderson insisted his charge is fine and working away as normal.
“The horse is going out to work now. Nothing has happened,” Henderson said. “I heard last night that he was drifting. Unless someone’s been in there in the middle of the night and hit him with a hammer then I don’t know why.
“It is most annoying because it’s the last thing you need. All that worries you. Nothing has happened.”
Meanwhile, two-time Gold Cup winner Kauto Star will have a racecourse gallop after Friday’s meeting at Wincanton.
The 12-year-old, who romped to his fifth King George VI Chase win at Kempton in December, suffered a fall while schooling last week which left him with a 50-50 chance of making it to Cheltenham, according to his trainer Paul Nicholls.