Froome won last year’s race by more than four minutes but Boradman, who rode in eight Tours de France following his golden career on the track, says that won’t be the case this time around.
“There will be more ‘close-call days’ than in recent editions,” said Boardman, who will be a pundit on this year’s race for ITV4.
“He’s had a lower-key build-up to the event this year, barely racing until the Dauphine, where he performed well but not at his usually high standard.
“Nairo Quintana and Jakob Fuglsang are amongst those capable of challenging the Brit for overall victory but (of the two) only Quintana has shown they can be consistent enough to be called true, tour contenders.
“Sadly, for those wanting to see a ding-dong multi-way fight, after the Giro, Quintana will only tire as the race winds it way through July.
“Froome on the other hand, with his steady start, is likely to improve as the race goes on.”
Chris Froome to win the Tour de France – 11/8
Boardman has highlighted stage 12 in the Pyrenees as the key stage of the race.
The 214.5km from Pau to the summit finish of Peyragudes is expected to sort the men from the boys.
Boardman explained: “With six climbs and a double-kick finish (there’s a little descent with 5.5km to go) anyone attacking on the penultimate ascent over the Col de Peyresourde will be hard to pull back, particularly if it’s wet. It’ll be a tough stage to control.”
While Froome will be very much on the radar in terms of the race for the yellow jersey, Boardman expects plenty of other British success – even if sprinter Mark Cavendish isn’t at his brilliant best.
Cavendish, winner of 30 Tour stages in his career, has been suffering from glandular fever this season but with no fewer than nine Brits entered this year, there are plenty of others to fill any potential void.
Boardman said: “Both the Yates brothers, Adam (not riding this year's Tour de France) and Simon, and Ben Swift have looked great already this year, as have Geraint Thomas and Peter Kennaugh.
“But being in the service of Froome, the latter two won’t get the opportunity to shine at this year’s Tour.
“The UK now has some serious strength in depth across all types of terrain, so expect to see GB riders contesting daily wins, especially in the medium mountain stages.
“And if Steve Cummings and Mark Cavendish can come back from early-season injury and illness in time, the law of averages says stage wins are the very least we can expect.”
To win a stage: Cavendish 4/7; Cummings 15/8; Swift 5/1
The 2017 Tour de France starts on Saturday. This year is the first time ITV4 will show every stage from start to finish live.
Click here for our full 2017 Tour de France guide
