Scotland assistant manager
Jordan Rhodes looks set to start in the lone striker's role in Scotland's friendly against
The 32-year-old Miller is embarking on a new role at Vancouver Whitecaps, a move perceived by some as him winding down his career.
But Miller has consistently stressed his continuing ambition to help Scotland reach a major tournament finals and Houston feels the former Rangers and Celtic man will be a key player in the Brazil 2014 campaign, which begins against Serbia on
Houston said: "
"We have to make sure we have players who can put Kenny under pressure.
"If Kenny is injured or not producing, then we have to find out who can take that role.
"But I think it would be wrong of us, because Kenny has gone to Vancouver that we rule him out.
"Kenny is still very fit, very quick and one thing is for sure, if you look at Jordan Rhodes and
"He upsets them and he has scored numerous goals at this level.
"But I still think Kenny is the number one striker."
Goodwillie came into the squad along with
The manager had already rested
But Houston is keen to make sure Scotland gets a result after its 5-1 defeat by USA in its previous outing.
"There has to be experimentation because of the players that have withdrawn," Houston said.
"There's five guys who could stake a claim to being in the first 11. Unfortunately they are out but it gives others an opportunity.
"But we have to make sure we are ready, this is a preparation for two very tough matches next month.
John Boultbee is set to relinquish his role as Football Federation Australia’s (FFA) Head of National Teams to take up a role as honorary head of World Rowing (FISA).