Two years ago Grindley went to Thessalonika as Britain's No 2 junior behind Mark Richardson, came back as European champion and has not looked back since. Last year he finished sixth in the Olympics, set a British record of 44.47sec and is among the favourites for a medal in this month's World Championships.
Grindley admits that he might not have achieved any of that if it had not been for winning in Greece. 'It showed me what I was capable of and really gave me the incentive to train hard during the winter,' he said.
The signs are good for Bullock. At 17, he is still young enough to run in next year's World Junior Championships but has been picked for the senior event - his reward for running so well in San Sebastian was selection for Britain's senior 4 x 400m squad in place of Roger Black, who pulled out with a virus. If he runs he will be the youngest person ever to represent Britain in the World Championships.
The news he had been called up was relayed to Bullock by David Cropper, the chairman of the selectors, almost as soon as he walked off the track after becoming the fifth successive Briton to win the 400m title. 'I thought I would be selected but it's still nice when you hear it,' he said.
There is a touch of arrogance about Bullock that means he stands out from his contemporaries. He was expected to win in San Sebastian. You only had to look at the form book to see that. But for the spectators in the Anoesta Stadium having their first look at the Liverpool youngster, it was the manner in which he patrolled the track in qualifying, as well as the continued backward glances, that caused them to focus their eyes on the broad- shouldered Briton.
In the final, he was five metres up on the rest of the field by half-way and was able to ease back on the accelerator as he eased down the home straight, once again continually checking behind him to see what was happening. That undoubtedly cost him the chance of the first sub-46 second time of his career, but his 46.13 was still a personal best and the winning margin of 0.71 was the biggest since Black took the title in 1985.
'I'm very confident in my own ability,' Bullock says. 'I don't think about coming second because if you do that you shouldn't even step on the track.'
Bullock was a talented schoolboy footballer and rugby union player until he took up athletics three years ago. He attended Liverpool's School of Excellence at Anfield as a centre-forward and in 1989-90 scored 92 tries for his school and his club from the wing. In the summer he sprinted but never used to do any training. He turned to athletics seriously after dislocating his shoulder and breaking his arm while playing rugby.
In his first 400m race he ran 51.2 to top the 1990 UK boys' rankings. He won the intermediates English Schools' title the following year and finished seventh in the World Junior Championships in Seoul last autumn. Earlier this summer he erased Grindley's name from the record books when he clocked 46.30 to set an English Schools' championship record.
He has trained with Grindley since joining his coach Chris Butler nine months ago. During the winter Butler had him and Grindley doing two-hour runs up Rivington Pike to build their endurance. In the spring he sent them to stay with Olympic 10,000m champion Khalid Skah in Morocco and train at altitude. There they used the thinner air to run faster than was possible at sea level and get their legs used to turning over quicker as they honed their speed. It is a programme unique among British sprinters.
Bullock, already 6ft 2in tall and weighing 12st, still has a long way to go before we see the finished article, says Butler, who believes ultimately he can run faster than Grindley. 'At the end of next winter people will see a marked difference in muscularity, because I will put a great deal of upper body strength on him,' he explained.
But if Bullock does not continue making the headlines he could always write them. He starts a media studies course in Southport next month and hopes to become a journalist.