The England captain, whose position Andrew Flintoff has assumed on a temporary basis, may return to international duty during the upcoming One-day series against Sri Lanka, which begins in a fortnight.
But Vaughan, whose knee injury raised fears for his career, owned up to feeling "a few aches and pains" after Yorkshire's defeat in Division One of the County Championship.
He made one and 56 with the bat, in his first championship match of the season, and said: "I know that it's hard for people to accept that I am playing for Yorkshire and not England but I am some way off being at an international standard of fitness at the moment.
"I have been hidden a bit in the field in this game and I have to make sure that when I come back for England I am 100 percent fit.
"I am still some way from being 100 percent fit and obviously have got a few aches and pains but my progress is on the rise."