Vaughan was Sunday confirmed as England's captain in the tri-series, taking over from Ashes skipper Andrew Flintoff.
It has been 18 months since Vaughan last played a One-day international and 13 months since he played a Test. Although he has recovered from knee surgery, he is yet to show how effective. he is in the field and running between wickets.
Buchanan wants his team to keep the heat on England after its pyschologically-damaging 5-0 Ashes series win, and defeat the tourists during the one-day series, which starts next Friday at the Melbourne Cricket Ground.
"We try to exploit any deficiency, whether it's technical, physical, mental or tactical," Buchanan told reporters here.
"If we understand that Michael's struggling physically, then that will be one area we will like to target.
"That will be the same with anybody. If we can detect weaknesses in their armoury, that will be an area we'll try to exploit."
Australia will use the tri-series as a chance to create a buffer between themselves and England and New Zealand ahead of the World Cup.
"Once we get to the West Indies (for the World Cup) we would have liked to have set a gap between us and two of the teams we'll face over there," Buchanan said.
"We'd like to have them in some form of disarray before they got there."
Vaughan averages only 28 in one-day cricket and has not scored a century despite playing most of his 74 matches in the top order - but his leadership could at least release the pressure on Flintoff.
Flintoff struggled with the responsibilities of the captaincy during the Ashes series, but Buchanan said the abbreviated game meant his powerful hitting and bowling made him a dangerous opponent, especially without the burden of the captaincy.
"The one-day game is a different format," he said.
"It shortens everything down so it brings both sides much closer together and one player can have an impact on the game rather quickly, of which he is definitely one."