Nick Rockett withdrawn from Grand National

Last year's champion, Nick Rockett, has been officially withdrawn from the upcoming Grand National race, scheduled for this weekend at Aintree. This development means that the defending winner will not have the opportunity to compete in the prestigious event this year. The withdrawal of such a high-profile entrant, especially the reigning champion, is a significant change for the race. It could potentially alter betting odds and the overall competitive landscape for one of horse racing's most anticipated events.