Lemi Berhanu Hayle will be hoping to repeat his 2016 Boston Marathon victory ©Getty Images

Ethiopian defending champions Lemi Berhanu Hayle and Atsede Baysa are among leading entires for two wide open Boston Marathon races due to take place tomorrow.

Hayle was a surprise winner in last year's event after winning a gruelling battle with another Ethiopian in 2013 and 2015 winner Lelisa Desisa.

The 22-year-old has since finished 13th in the Olympic Games before a victory in January's Xiamen Marathon.

In Desisa's absence, other frontrunners this time around should include Kenyan duo Emmanuel Mutai and Patrick Makau. 

The pairs respective personal bests of 2hours 03min 13sec and 2:03:38 rank them each among the 10 fastest marathon runners in history.

Two other past Boston champions are among the entries. 

Kenyan Member of Parliament Wesley Korir will be hoping to repeat his 2012 victory while home hope Meb Keflezighi was the champion in 2014.

United States' challenge will also include Olympic bronze medallist Galen Rupp.

He will be hoping to convert his championship pedigree into a fast time after a year in which he has battled plantar fasciitis injury. 

Olympic medallist Galen Rupp is an intriguing Boston Marathon entrant ©Getty Images
Olympic medallist Galen Rupp is an intriguing Boston Marathon entrant ©Getty Images

The International Association of Athletics Federations Gold Label and World Marathon Majors Series race is not eligible for record purposes due to the overall drop of 140 metres.

But the men's entries will be hoping to take advantage of a tailwind to challenge Geoffrey Mutai’s course record of 2:03:02 set in 2011.

Baysa has only raced once since winning last year in a relatively pedestrian 2:29:19.

Kenya's Caroline Rotich, the 2015 winner, is among her rivals as well as fellow countrywomen and 2014 champion Buzunesh Deba.

Kenya’s 2014 world half-marathon champion Gladys Cherono time of 2:19:25 clocked at Berlin in 2015 makes her the fastest in the field, although she has little recent form over the 26.2 miles distance.

Former London and New York City winner Edna Kiplagat is another leading Kenyan entry.

Tomorrow's race will also mark the fourth anniversary of the Boston Marathon bombing in 2013 in which three people were killed after two homemade devices were triggered at the finish line.

The elite women are due to start racing at 9:32am local time, with men following with the first wave of the mass start at 10am.