And the straight-talking Kiwi has laid down the law over the strict fitness levels expected from his players ahead of October's tournament.
Pontypridd lock Cockbain, brother of Queensland and Wallaby star Matt, has qualified for Wales on residency grounds after three years in his adopted country and the 6ft 8in giant is among 25 additions to the tour party for the provisional World Cup squad.
Among the other names included in the 55-strong group are young flanker Rhys Oakley, signed by Gwent from Bristol and South African-born centre Hal Luscombe while there is space for Grand Slam winning under-21 players Gavin Henson, Nicky Robinson and Jonathan Thomas.
'We will be casting a physical net over these players in terms of conditioning and fitness,' said Hansen.
'All of them will be put on training programmes by national fitness coach Andrew Hoare and monitored by their regions.
'But this does not exclude anyone else as I'm sure people will drop in and drop out of the group according to performances or if they are not meeting their fitness requirements.'
Also named were several fringe players who missed out on next month's tour to Australia and New Zealand such as British Lion Dafydd James, Martyn Madden and Ian Gough.
Wales play a series of friendlies against England, Scotland and Ireland in consecutive weeks in August before Hansen name's his final squad.
'We've got a series of friendlies and then pre-season games for all of the provinces in September which we will be watching closely,' he said.
Wales Preliminary Summer Training Squad:
(Backs) G Evans, K Morgan, R Williams, M Jones, C Morgan, G Thomas, D James, M Taylor, J Robinson, T Shanklin, S Parker, A Marinos, H Luscombe, M Watkins, L Davies, G Henson, I Harris, S Jones, C Sweeney, N Robinson, D Peel, R Powell, G Cooper, M Phillips.
(Forwards) I Thomas, A Jones, G Jenkins, D Jones, B Evans, M Madden, R McBryde, M Davies, H Bennett, G Williams, M Rees, R Sidoli, G Llewellyn, V Cooper, C Wyatt, Deiniol Jones, I Gough, J Thomas, M Owen, J Bater, S Williams, B Cockbain, R Oakley, G Thomas, Dafydd Jones, M Williams, C Charvis, R Parks, G Delve, A Popham, R Sowden-Taylor.