Both riders have all but dominated the classics so far this season, with Van Avermaet completing an impressive triple winning streak at Omloop Het Nieuwsblad, E3 Harelbeke and Ghent-Wevelgem.
Defending Flanders champion Sagan, meanwhile, has not been far from the action, having won Kuurne-Brussels-Kuurne and placed second in Milan-San Remo and Het Nieuwsblad, plus third at Ghent-Wevelgem.
Resurgent cobbles man and current Belgian road race champion Philippe Gilbert (QuickStep-Floors) is also rated highly by the bookies – more so after his convincing solo win in the opening stage of the Three Days of De Panne on Tuesday.
Alexander Kristoff (Katusha-Alpecin), Michal Kwiatkowski (Team Sky) and John Degenkolb (Trek-Segafredo) are also among the favourites, along with one oddity: Geraint Thomas. According to Odds Checker, many are offering odds of 20/1 - best avoided.
The Team Sky Welshman is sitting out the classics this year as he focuses on the Giro d'Italia, something which has evidently passed many of the bookmakers by.
There are several riders who could figure highly in Flanders who appear further down the bookies' list of favourites: Tom Boonen (Quick-Step Floors), Sep Vanmarcke (Cannondale-Drapac), Luke Rowe (Team Sky), Arnaud Démare (FDJ), Edvlad Boasson Hagen (Dimension Data) and Ian Stannard (Team Sky) among them.
Bet 365 was offering odds of 40/1 for Rowe on Wednesday morning.
The 2017 Tour of Flanders takes place in Belgium on Sunday, April 2. The gruelling 260.8km route includes 18 climbs and cobbled sectors. Crashes and mechanical mishaps can play as much a part of the race as strength, stamina and tactics.
Last year, Van Avermaet was forced to abandon the race with 100km remaining after a heavy fall.
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