The 20-year-old was released by Tranmere in November 2012 but swiftly returned to action with Scottish Championship side Falkirk three months later.
Wirral-born Vaulks was picked up by Falkirk after impressing scouts whilst plying his trade with non-league Workington in the Conference North.
Vaulks, whose versatility lends him to both full-back and centre-half berths, now has the chance to impress Rovers boss Gary Bowyer at the club's Brockhall training base.
Although keen to retain Vaulks' services, Falkirk manager Gary Holt admits trialling with a Championship club offers an excellent opportunity to the defender.
"I don't want to lose him, or anyone at the club, but we know the situation here and if an offer was to come in we'd have to look at it," Holt told the Falkirk Herald.
"Blackburn is a big club and it's a big opportunity for Will.
"He won't go down there unknown to the Blackburn manager Gary Bowyer - they'll know all about him.
"A trial period isn't unusual. Clubs often do it with young players to assess them closely and monitor how they fit and settle with the group and how they handle training."
Blackburn have also been linked with Liverpool winger Jordan Ibe, with the Reds keen to secure a loan move to the Championship for the 18-year-old.