The 23-year-old forward moved to Kenilworth Road from non-league Truro City last summer, and went on to score 16 goals in 54 outings for the Hatters.
Isaac Vassell of Luton Town in action
The Luton man impressed all season long in League Two, showcasing his exceptional work ethic, and the unselfish manner in which he goes about his business by bringing others into play.
And the Sun's Alan Nixon claims that the Blues and the Robins are keen to add Vassell to their ranks this summer, and will go head-to-head in a race for his signature, with both clubs ready to offer Luton £1 million.
The step up from League Two to the Championship is a huge one, however, and the 23-year-old could very well struggle initially to adjust to the intense nature of England's second tier.
For just £1 million though, it will surely be worth taking a risk on the former non-league ace, because who knows, he might be the next Jamie Vardy.
Isaac Vassell of Luton Town celebrates