The Sydney 2005 premiership coach said last Friday night he was a "50-50" chance to coach the Demons.
Roos said getting the approval of his family was a crucial step in the process and he wanted to wait until his wife and eldest son return from a trip to Bhutan before making a commitment.
"They're the most important thing for me," Roos told Fox Footy's On The Couch on Monday night.
"If any of them said no, it's a no.
"I think Tami and Dylan arrive back on Tuesday morning about 8 o'clock."
But he said that was not the only factor, as he was yet to be completely certain in his own mind that he was ready for the commitment coaching involved.
"That's really what it is at the moment," he said.
"It's just saying, to be fair to the Melbourne Football Club and the players and the members and everyone like that, you've got to be fully committed to do it."