For the event to have managed to stage elite racing in a year when virtually every other big city marathon had to cancel because of coronavirus fears is a mini-miracle, and for all the disappointment and letdown of Bekele’s regretful announcement it would be perverse not to fully savour the range and quality that will still be on show over the closed, looped 1.3 miles course within St James’s Park.

The absence of the Ethiopian who last year came with two seconds of his official world record of 2 hours 01min and 39sec should make it substantially easier for Kipchoge - who last October became the first runner to complete a marathon in less than two hours - to embrace yet another historical distinction in becoming the first able-bodied athlete to win five London titles.

As things stand he is tied on four victories with Norway’s Ingrid Kristiansen.

But before Kipchoge can put himself to the latest test, tomorrow’s activities will start at 07.15am with the women’s elite race, in which his compatriot Brigid Kosgei looks capable of setting a world record for a women’s only race having broken the mixed racing mark in Chicago last October with a time of 2:14:04.

That effort eclipsed the mark of 2:15:25 set by Britain’s Paula Radcliffe at the 2003 London Marathon.

The women-only world record of 2:17:01 was set by Kosgei’s compatriot Mary Keitany at the 2017 London Marathon.

In the build-up to tomorrow’s racing Hugh Brasher, the Virgin Money London Marathon event director, told insidethegames that due to the disruptions to training and competing brought about by the coronavirus pandemic there was more uncertainty about this version of the event than ever before.

He characterised it as "the most unpredictable ever", a sentiment that has since been echoed by numerous entrants in both the running and wheelchair racing events.

But it will nevertheless be a huge shock if anyone other than Kipchoge now wins the men’s race, or Kosgei the women’s.

Like every other athlete in the world, Kipchoge’s training has been disrupted by the pandemic, and he had to work on his own for a period after the closure of his training camp in Kaptagat, Kenya, although he has more recently been able to return to training in a group.

"It was really difficult when I had to train on my own because for 17 years I have been training with six, 10 or 20 people all year round," said Kipchoge.

"So, it was like an electric shock when I had to train on my own.

"It was hard to get fit and up to a high level of training.

"But lately we have consolidated a bigger team around me and training has been good."

In the run-up to the originally planned date for the race on April 27, Kipchoge spoke about targeting the course record of 2:02:37 he set last year, and that looks possible if he can adapt happily to running around in circles.

His experience last year on the equally flat looped course around Vienna’s Prater Park in the staged event that saw him through the distance in an astounding 1:59:40 may prove to be especially useful tomorrow.

Asked to confirm reports that pacers plan to reach the halfway point in 61 minutes or faster, Kipchoge politely demurred, although he did say that "61 would be okay".

In Bekele's absence, Ethiopia's Mosinet Geremew and Mule Wasihun appear most likely to take the challenge to Kipchoge.

Both tried valiantly in last year’s race, hanging on to Kipchoge’s coat-tails until two miles from home and recording two of the fastest marathon times in history - Geremew’s clocking of 2:02:55 to finish second puts him fourth on the world all-time list.

Other athletes to watch are Sisay Lemma, Tamirat Tola, Marius Kipserem and Shura Kitata, all of whom have run inside 2:05.

Kosgei, the defending women’s champion, will also have to be in top form to hold off a talented field.

But her superb showing in last month’s one-hour track race at the Wanda Diamond League meeting in Brussels - where she gave the eventual winner and world record breaker Sifan Hassan a fierce race, also finishing inside the old mark before being disqualified for an isolated single step onto the infield in the closing stages - offered clear evidence that she is in terrific shape.

Kosgei nevertheless sounded less than ecstatic about running on the looped course - another unfamiliar experience for her.

If this 26-year-old mother of twins gets spooked by the weirdness of the experience on a course without spectators then her compatriot Ruth Chepnegetich, who ran on a looped course on Doha’s Corniche last October to win the world marathon title, will surely capitalise.

Another redoutable Kenyan, the 2018 London champion Vivian Cheruiyot, will also be ready to pounce on any weakness, although Kosgei beat her convincingly to win her first London title last year, finishing almost two minutes ahead.

Britain’s Sir Mo Farah, who has put his road running ambitions on hold as he refocuses on defending his Olympic 10,000 metres title in Tokyo next summer, will be pace-maker for a group of male runners chasing the Tokyo Olympic qualifying standard of 2:11:30.

These include the Briton who followed Farah home to earn silver in the 2010 European 5,000 metres final, 39-year-old Chris Thompson.

A number of female runners will also be chasing the women’s standard of 2:29:30, including home runner Lily Partridge.

A world record number of 45,000 entrants will be working out how they can best cover the marathon distance tomorrow while being tracked by the official London Marathon app.