Mr Ross called for urgent talks with the leaders of Scottish Labour and the Liberal Democrats, saying they needed to unite to resist Mr Salmond’s attempt to “game” Holyrood’s electoral system.
Mr Salmond is to place candidates for his new Alba Party on the list in every region of Scotland to create an independence “super-majority” for Scottish independence.
Mr Ross warned the other parties were being “naive in the extreme” if they did not accept the “very real” possibility that Mr Salmond’s plan could work.
Previous suggestions the parties could work together have been dismissed by Liberal Democrat leader Willie Rennie and Scottish Labour leader Anas Sarwar.
Last week, Mr Sarwar said he did not think Mr Ross’s idea they could work together was “serious” and admitted he had never had a conversation with the Scottish Tory leader, who is currently an MP in Westminster.
Mr Ross told the Daily Telegraph that he was willing to discuss the possibility of withdrawing Tory candidates in seats where his party is not likely to have success, to ensure the pro-union vote is not split.
Possible seats which could see the withdrawal of Tory candidates include Glasgow Southside, where Mr Sarwar is in battle with First Minister Nicola Sturgeon, or North East Fife, where Mr Rennie is standing.
Asked whether he would be willing to consider withdrawing his own candidates, Mr Ross said he was ready to “look at every and all options”.
He said: “They would put forward proposals, I would put forward proposals, but at the moment, given the threat that we’re facing, nothing is off the table.
"We are actually in second place in many places across Scotland, so it is clear that the Scottish Conservatives are the strongest anti-nationalist party across much of Scotland. But that doesn’t stop me from recognising that there are opportunities to work together with Scottish Labour and the Scottish Liberal Democrats if they’re willing to do that.”
He added: "I think it's naive in the extreme of Anas to suggest that we can somehow ignore the threat that is being posed by the SNP and the Alba Party. And that's why my offer continues to be there to Scottish Labour and the Scottish Liberal Democrats.
"We don't agree on everything, but we should agree on the threat the nationalists now pose to Scotland, and to the United Kingdom, and work together to stop that. We don't have much time, which is why I'm asking Anas, I'm asking Willie, to sit around the table."
Scottish Liberal Democrat campaign chair Alistair Carmichael MP said: "The only person more desperate to talk about independence in this election than Alex Salmond and Nicola Sturgeon is Douglas Ross In his case it is because it distracts attention from his links with Boris Johnson and his mishandling of the pandemic.
"We want to talk about how we lead Scotland towards recovery. Douglas Ross wants to talk about pre-election carve-ups. The voters can decide which approach they prefer.”
A number of SNP politicians have announced plans to defect to Mr Salmond’s Alba party.