He might not be a familiar name, and you wouldn't recognize him in the street - but go to his gym and you'll soon know who he is!
The players who have volunteered for his programme certainly do.
"Traditional fitness work has been restricted to the lower body with everything else an afterthought," says Dave, known as the 'Bodydoctor'.
"I work with John Green mainly on the upper body."
Dave is a regular at Chadwell Heath, putting the players through their paces with the weights.
His being at West Ham is symptomatic of how the game is getting more sophisticated when it comes to training techniques.
"The game has changed a hell of a lot; players eat right, they sleep right, and now they work right," says Dave.
"A lot of it has got to do with the continental boys coming in.
"You can't just train and go off and have pie and mash and ten lagers afterwards.
"Foreigners have never had a drink culture and none of the boys here drink.
"You can tell if someone does no matter how much they exercise because they just puff up.
"The work with me is in addition to training, they don't have to do it.
"But if you can get that extra edge over the opposition, you take it.
"Paolo was misquoted earlier in the season with the comment about not training hard enough.
"Other clubs have been looked at, and they don't do what we do.
"Harry, Roger, Frank, and Glenn work the boys very hard.
"The players are very dedicated and want to do better.
"And people like Joe, Michael, and Frank have not been exposed to the previous culture of 10-15 years ago.
"These guys have serious ambition and want to make a championship side.
"That is not pie in the sky, these guys have got real talent."
Dave, a West Ham fan, adds:
"Traditional weight work makes you slow and laborious - and you run like a gorilla at half pace.
"Here it is to do with strength; people think of little Joe but he he works hard and has a lot of strength for a little 'un.
"Players hit him and bounce off!"
Dave has worked with many stars, including Robbie Williams and Les Ferdinand, but it is his travails with the West Ham stars that is his real labour of love.
"I work in a different way to other fitness people," he stresses.
"It is geared to increasing power and losing body fat, and it's all about lean, usable muscle."
For Dave, being with the players is a reminder of what might have been...
"I always wanted to play for this lot, but my knee got wrecked when I was 16 and I had to drop levels.
"And the lower you go, the more brutal it gets," he says.
As for bodies beautiful, he says:
"Stuart Pearce is a one-off; he works incredibly hard and it is as if he has no wear and tear on his body."
Dave hopes the benefits of his programme will help put points on the table for West Ham by giving the players that physical superiority over the opposition.
He says:
"Look at players like Heskey, Hasselbaink, and Stam: they have got a physical advantage.
"If you took Heskey's physical strength away he'd be a very ordinary player - it's not as if he is mega talented.
"I want to give everyone at this football club a physical edge.
"Initially Fredi was reluctant to get involved but he saw others doing it and now he loves it.
"If they weren't happy with it they wouldn't have me here."
John Moncur is a big fan of the programme and says:
"I've enjoyed doing it - and it really works!"
Dave is offering a mail order book for a limited period at the reduced price of £35.
Or you can have a "soft copy" of the fitness and nutrition manual for just £15.
If you are interested, please forward payment to Dave Marshall at Bodydoctor Fitness Ltd., PO Box 20641, London NW6 4ZA.
Print your name, address, contact details, and bank sort code and allow 21-28 days for delivery.
You can contact him by phone on 020 7586 6222 or by email on [email protected]
Or, indeed, you can look at the websites at www.bodydoctorfitness.com and www.bodydoctor.com. You can also have a personal workout course with Dave for £1,500 which includes an assessment and 18 sessions.
As he says in the programme, "the training sequences that I employ are in complete contrast to the same old sequences that have been churned out for the last 60 years.
"Your results can be as good as you want them to be."
* Hayden Foxe is getting on the score sheet as Australia romp through the Oceania world cup qualifying group.
He grabbed one in the 2-0 win over Fiji [hmmm - tight game!] and two in the 11-0 win over Samoa.