Porte has started the season reasonably well, finishing second at the Tour Down Under and then taking second again in the Australian national time-trial championships, behind BMC teammate Rohan Dennis.
Dennis would have been amongst the favourites for Sunday's opening prologue but has been forced out of Paris-Nice by illness.
That has put a dent in BMC's preparations and could put more pressure on Porte to deliver the overall title, not that the Tasmanian is feeling it.
"Paris-Nice is a really solid race in the early part of the season and a good way to test my form," he said.
"I'm going into the race this year with less expectation than in previous years and see it as another opportunity to get some more race days in the legs."
The competition should be stiff with two other former winners in the field in Spanish veteran Alberto Contador (2007 and 2010) and Luis Leon Sanchez (2009).
Several youngsters could also feature in the shape of Frenchman Romain Bardet, a top 10 finisher at the last two Tour de France editions, Dutchman Tom Dumoulin, sixth in last year's Vuelta a Espana, or even Briton Simon Yates, fifth at last year's Criterium du Dauphine.
Sky's bid will be led by Welshman Geraint Thomas, who finished fifth last year despite being there to help Porte.
Thomas has been in good form already this year, retaining his title in the Tour of the Algarve.
However, the course is more suited to an out-and-out climber with the ascent of Mont Ventoux on the fifth stage and seven categorised climbs on the penultimate stage the next day.
Yet many cobbled one-day classics specialists are using the race to build form ahead of the meaty portion of the Spring Classics season.
Former Paris-Roubaix winners Tom Boonen and Niki Terpstra will line up for Belgian outfit Etixx-Quick Step, along with Astana's Lars Boom, who won the 2014 Tour de France stage that borrowed some of Paris-Roubaix's cobbles.
Following a 6.1km prologue on Sunday, three of the next four stages are flat, favouring sprinters such as Germany's Marcel Kittel, while the third-stage finish on Mont Brouilly is tailor-made for specialist punchers.
The fifth and sixth stages in the mountains should decide the overall winner, although the hilly final run into Nice on Sunday, March 13 does offer chances to snare some seconds.