Felgate doesn't talk to Henman like that any more. The raw youngster he took charge of has come on a bit since they first started working together, when the idea that the country might produce someone capable of holding his own, still less triumphing, on the biggest stages would have seemed frankly preposterous.
Now Henman is that someone - ranked, as of this week, No 26 in the world, recognised way beyond the boundaries of British tennis while transforming its image almost single-handedly. As the time approaches for votes to be cast in the BBC Sports Personality of the Year award, Henman must be right up there in contention with Steve Redgrave and Frankie Dettori. This week he is looking to take another step forward in Ostrava, with more prestigious tournaments in Stuttgart, Paris and Moscow to follow.
Like many successful player-coach relationships - the late Tim Gullikson and Pete Sampras is perhaps the best example - Felgate's with Henman is professional only in the sense that the hard work doesn't let up, and training and match preparation are still done with the thoroughness that is a pre-requisite for success. The teacher-pupil days have long gone, however.
"I'm certainly not kowtowing to him just because he's a better player now," Felgate said. "If I feel I need to say something I won't shy away from it. I'll choose my moment. But he's a mature young adult. Of course I couldn't treat him like I might once have done. We've become very good friends."
The importance of the partnership to Henman's growing stature, and indeed to Felgate's, cannot be overstated. For it is not just Henman who is glowing with satisfaction these days. With no great track record as a player, the 33-year-old Felgate has found his metier in coaching Henman, and those who were sceptical of his ability to take his man all the way are having to acknowledge the scale of his achievement. "It's given me more credibility, and that pleases me," Felgate said. "It's not that I want to be going round sounding off all the time, but when I do have something to say, I feel people are going to listen."
Ever since it became clear that Henman was going to be hot property, envious eyes have been cast at Felgate's position, and there are senior figures in British tennis who have attempted to undermine it. "From early on, there have been people saying maybe he needs a different coach," Felgate said. "But who did Tony Pickard coach before he had Stefan Edberg? Was Bob Brett [former coach of Boris Becker and Goran Ivanisevic] ever a decent tennis player? That sort of thing irks me a lot."
Felgate has been in a slightly vulnerable position because for the last two years he has had to combine coaching Henman with his job as head of men's national training at the Lawn Tennis Association. There was a feeling that the two roles were not so much incompatible as simply over-burdensome. One of them would have to go.
Now it looks as if Felgate may be about to make a break from the LTA and move into a role in which Henman would employ him as his coach on an exclusive, full-time basis. Nothing is yet official, but for some months this has been a development which has seemed more a matter of when than if. Jeremy Bates, the recently retired former British No 1, is Felgate's deputy and would make a logical successor, while Henman has reached a stage when, even though Felgate has been available to him for as long as he has wanted, the arrangement needs to be nailed down.
"David has a very good understanding of my game," Henman said last week, when he had a welcome week back in England while he nursed the blisters caused by his run to the semi- finals of the Lyon tournament. "It's a learning process for both of us. We're in it together."