Fresh from claiming his 300th Test victim on Monday in the Sydney Test, his 63rd, Warne quipped after hearing his mentor's comment that he would be rolling in and bowling from an armchair by the time reached 600 and wondered whether Jenner had had a drink or two.
But Jenner, who played nine Tests as a leg-spinner for Australia in the 1970s, is a highly astute reader of the game and the one person who knows Warne's bowling as well as the man himself.
``Shane's not as venemous as he was a few years ago,'' Jenner says. ``Between 24 and 26 he was absolutely dominating, but because of the number of balls he bowled he had to have that op on his spinning finger. What happened after was that he didn't have the same feel in the finger, and feel is so important for the wrist-spinner.''
To the cricketing fraternity, Warne returned from his operation no less a potent force, turning the ball prodigiously in his first two Tests back against the West Indies, both of which he helped win. But after the second, he went to the nets with Jenner, who takes up the story.
``Shane started off with a couple of rippers that turned square and I shouted that anyone would kill to bowl those. He replied that it just didn't feel right.''
Warne, according to Jenner, did not re-discover his feel or best form on either the tour to South Africa or England that followed, nor the home series against New Zealand in November.
``It came back here in Sydney,'' Jenner says. ``He was excellent in Melbourne, although the variety was missing a bit, but now I think he's got used to the feel of his finger after the op.
``I'm sure because if he has any negative thoughts about his bowling, he'll call me. Over these last two days he didn't. That's my job -whenever his thinking is negative to convert it to being positive.''
It is a job which Jenner does supremely well. Yet he knows that Warne is still a different bowler from his early days.
Mark Taylor, who has had the best view of Warne from slip along with Ian Healy, concurs. ``In Zimbabwe in 1991, when he burst on the scene, he bowled these huge leg-breaks and the flipper. Now his topper and wrong 'un are better. The flipper is not quite the weapon it was, but overall he has more weapons.''
More weapons should mean as many wickets for Warne - who has replace Glenn McGrath as No 1 bowler in the Coopers & Lybrand Ratings - over the next few years, fitness permitting.
The last word is Jenner's. ``Now he's over the finger op, he should be OK. The other thing about Shane is his grip on the ball - it's the slackest of any spinner I've ever seen. That could add years to his career.'' Not good tidings for England if Jenner is correct.
Fast bowler Glenn McGrath has been rested from Australia's squad for the next two World Series one-day matches because of a minor thigh strain.
The triangular one-day series resumes on Friday when South Africa take on New Zealand in Brisbane. Australia then play South Africa at the same ground on Sunday before meeting New Zealand in Sydney next Wednesday. South Africa lead the competition with six points from four matches.
In two squad changes, Australia recall Stuart Law at the expense of the veteran all-rounder Tom Moody, while Darren Lehmann replaces the opener Michael Di Venuto.