Frankel's foal goes up for auction in just over an hour.
Together with his mother, Crystal Gaze, who is expecting a second foal by the undefeated Newmarket racehorse, he could fetch more than £1m at the auction at Kensington Palace.
Henry Beeby, chief executive at auctioneers Goffs, said: "Frankel was the greatest racehorse we had ever seen. He was undefeated. He was spectacular. And he was an absolute star.
"It's a bit like Usain Bolt turning up at stud."
Click below to hear more from Henry Beeby.
More top news
Some sunny intervals are possible initially this morning but cloud and patchy rain will gradually sweep in as the day goes on.
The final score was Northampton 24 - Saracens 29 at Franklin's Gardens.
The Anglia region looks likely to enjoy a drier and sunnier spring than normal in 2015 although temperatures are near normal.