With a number of experienced players retiring after the World Cup in Australia last year, Williams will go into the championship without the likes of captain Bryan Redpath, Gregor Townsend, Kenny Logan, Glenn Metcalfe and James McLaren - bringing the average age of the new-look squad down to only 25.
There may be more changes as Williams searches for the right blend. But he believes that in newcomers Chris Cusiter, Gareth Morton, Dan Parks, Tom Philip, Simon Cross and Allister Hogg he has the nucleus of a team which can do Scotland proud in the coming years.
Williams, who has named stand-off Chris Paterson as his new captain, asked: "We've got to do it - have faith in the young. Rugby's a renewable resource - give young men a go; give them a chance.
"There's a lot of good young guys there that we need to give a chance to, especially in the backs.
"We've lost five players, but there's five very good young backs, a couple of good young back-rowers, some specialist open-side flankers - which after Andy Mower's injury and Budge Pountney's retirement, there's a pretty strong need for. Cometh the hour, cometh the man."
Williams will be prepared to give his new charges time to prove themselves, and the door remains open for those who have been replaced too.
"We haven't played a game, so we don't know how people will react,"he pointed out.
"We're not discarding players - and even the players who have just missed out certainly aren't being discarded. That is our message. We have an Australian tour coming up.
"We see the next 18 months as the time for this team to develop. We're definitely going down to win the Test (against Wales) - we're not suggesting anything else - but we will develop over the next 18 months.
"There are players who are outside this squad who will come in; there are players who are in the under-21s who will come through. Right now, that's the squad we believe will do the business for us in this particular fixture."
Williams has brought a number of former internationals on board in what he terms a 'national team mentor group' - which will headed by British Lions Gavin Hastings and Finlay Calder.
It is a step in the right direction, according to Calder who said: "I think John Jeffrey made the point a month or so ago that there wasn't one former international who wasn't prepared to help in some shape or form.
"I think that message is loud and clear. We are desperate to help, and I am extremely honoured to be invited to help."