The 39-year-old, who won an emotional victory last year on the first anniversary of the bombing at the course which left three dead and hundreds injured, offered his support to a Games bid that has provoked distinctly mixed feelings among the local public.

“I’m honoured to be participating with the Olympic bid and endorsing it,” the three-time Olympian and Athens 2004 silver medallist told the Boston Globe.

“I hope to do more community outreach, to explain what hopefully can happen, and how it can be looked at as a glass half-full  instead of half-empty to have the Olympics in Boston.”

Keflezighi said he intends to stay involved with the Olympic bid after the race, perhaps by rallying volunteers, which would be needed by the thousands if Boston were to host the Games, and by rallying public support.

“You need unity of the community, unity of the city, in order to make it happen,” he said.

“Somebody will be happy, somebody will be upset, and obviously it cannot satisfy everybody but hopefully we can meet halfway, with commitment and sacrifice in a common goal to make it a reality.

"Not just for Boston, for America.”

Boston 2024 officials and Keflezighi intend to meet after the Marathon to brainstorm on ways he can stay involved with the bid, Erin Murphy, the bid committee’s chief operating officer, said.

“Meb is universally loved and respected for his achievements and we are so honoured to have him be part of this," she added.

“He’s just an inspiring person to be around.”

Meanwhile, Boston 2024 is planning a sports-themed promotional push at tomorrow’s race.

About 120 volunteers, dressed in Boston 2024 T-shirts, will be at the airport and at North and South stations throughout the weekend to help visitors “navigate the city and feel welcome”.

The bid committee will also have a booth at the John Hancock Sports & Fitness Expo at the Hynes Convention Centre this weekend.

“Our partners at the [Boston Athletic Association] have been very supportive and we’re in lock step on how meaningful the marathon can be to rallying the running community’s support of Boston 2024,” Murphy explained.

Last month the latest poll of voters showed 52 per cent opposed the bid.

But a WBUR poll released last week suggested Greater Boston’s support for an Olympic bid in April stood at 40 per cent - up from 36 percent in March.

The potential for Olympic cost overruns appears to be a top concern among voters.

Boston 2024 has called for a referendum on the bid next year and says it will not move forward unless it wins a majority state-wide and within Boston.

Keflezighi will defend his title without undue pressure.

He is only the 13th best in a men’s field which includes the 2013 Boston Marathon winner, Ethiopia’s Lelisa Desisa.

The latter’s record of having finished first or second in every major race he has finished over the last two years makes him the favourite to triumph again.

The women’s title is also likely to go to Ethiopia thanks to the presence of four runners with the fastest times in the field, notably Mare Dibaba and Bizunesh Deba, respectively runners-up to Kenya’s Rita Jeptoo at last year’s Chicago and Boston Marathons.

Jeptoo is now serving a two-year doping ban after testing positive for EPO in September.

But there are chances for another home flourish in this race through Shalane Flanagan, seventh last year, who has improved her personal best to the point where she is only 1min 22sec off the fastest woman in the field, Dibaba.

Another leap forward for Flanagan could give her a chance of becoming the first US woman to win Boston in 30 years, since Lisa Larsen Rainsberger won in 2:34.06.

Two years earlier, the about-to-be debut Olympic champion Joan Benoit set a world record of 2:22.43 with her second Boston win.

“I feel really optimistic and excited about this year, just because we don’t have [Jeptoo] in the race,” Flanagan told media in Boston.

“That makes me feel like the possibilities are open and endless for anyone.

"It’s not like decided before the race who’s going to win.”

Related stories
April 2015: Boston 2024 bid on "much more positive track" soon claims USOC chairman
March 2015: Boston 2024 and USOC deny bid to be dropped if public support does not improve soon
March 2015: Top Americans join 2015 Boston Marathon field as Ethiopian drops out
April 2014: Keflezighi and Jeptoo win Boston Marathon one year on from deadly bombing
April 2013: Boston Marathon finish line explosion leaves people dead