East Renfrewshire's area commander told The Extra: "It is something which may come to pass but will take years, rather than the 12 months being discussed".
CI Graham confirmed that the idea of amalgamating Scotland's eight forces had "been mooted for many years".
But he added: "Personally, I believe it won't happen in my policing lifetime".
Talk of a merger was renewed more recently when justice secretary Kenny MacAskill pointed out that the country cannot afford to do everything "eight times over".
He also warned that Scotland's police forces faced "unprecedented challenges".
Strathclyde's chief constable Steve House has said that Scotland "could be well served by a single police force, not because it would be the cheapest but because it would be the most effective model.
"What is clear, however, is that the financial situation is going to be a great deal worse than anyone had expected.
"If we can make big savings by merging forces or by any other means, then it is our duty to consider that seriously".
Meanwhile, CI Graham added: "We can't work harder than we do but we will have to look at efficiency and effectiveness to address the challenges from the budget shortfall and decrease in funding".
President of the association of chief police officers in Scotland, Patrick Shearer of Dumfries and Galloway, met with fellow chief constables and their senior colleagues from all Scottish forces to discuss impending challenges to the country's policing.
He confirmed that a task force would be led by senior officers to carry out "a thorough examination of all the options open to us".
The aim, he said, was "to ensure that we work as efficiently as possible and are well prepared to face what will be significant cuts in our budget over coming years".