Tremain, 22, has been recruited from New South Wales after Victoria also flirted with the recruitment of the allrounder Sean Abbott.
In six Sheffield Shield matches for the Blues, Tremain has bowled decently, claiming 18 wickets at 31.72 including six for the match on debut against Victoria in 2012.
"We are really excited about Tremain - he is a 22-year-old fast bowler who bowls with good pace and outswing," Victoria's state talent manager Andrew Lynch said. "He suffered from a lack of opportunities at New South Wales but we think we can give him that."
Haberfield has been granted a state contract having already played two Shield matches for the Bushrangers last season following his move from South Australia.
Capable of bowling at a slippery pace, Haberfield also has an enviable domestic limited overs record from his time with the Redbacks, and led Melbourne's club wicket-takers for 2013-14 as he spearheaded Footscray-Edgewater to the premiership.
"He had a great year and performed in the big games, taking his side to a premiership," Lynch said. "He certainly wasn't out of his depth in his two matches with the state side and was probably unlucky not to have played more."
After more than a decade of consistent success, Victoria hit the wall last summer, the change of captaincy from Cameron White to Matthew Wade not translating into strong results for the team even though it allowed White to enjoy his most productive season in some years and return to Australia's Twenty20 side.
The Bushrangers have also lost their long-term assistant Simon Helmot as he expands his freelance T20 coaching portfolio, leaving the experienced mentor Greg Shipperd to wring new life from a squad that struggled for traction across the summer, even as the state provided a solid contribution to the national team.
A transition of eras has been emphasised by David Hussey's retention in a player-coach capacity, where he will captain the state's Futures League team while also mentoring the batsmen in the squad.
Victoria squad: Fawad Ahmed, Scott Boland, Dan Christian, Aaron Finch (CA), Peter Handscomb, Jake Haberfield, John Hastings, Jon Holland, David Hussey, Alex Keath, Glenn Maxwell (CA), Clint McKay, James Muirhead, James Pattinson (CA), Rob Quiney, Jake Reed, Chris Rogers (CA), Peter Siddle (CA), Ryan Sidebottom, Marcus Stoinis, Chris Tremain, Matthew Wade, Cameron White. Rookies: Ben Ashkenazi, Aaron Ayre, Louis Cameron, Guy Walker, Matt Short, Seb Gotch
Daniel Brettig is an assistant editor at ESPNcricinfo. @danbrettig