Cracknell is unlikely to make a full-time return soon

Cracknell, who has not raced since the Athens Olympics, answered an emergency call from coach Jurgen Grobler to race in the Head of the River Fours race.

"It's very flattering to be asked," said Cracknell, who will row for Leander Club in the London event.

"I'm quite fit but I haven't done any high intensity work recently."

Cracknell, 33, announced last November that he was taking a year away from the sport, prompting speculation he would follow team-mate Matthew Pinsent into retirement.

He is unlikely to return to the sport full-time in the near future as he is about to row to the Caribbean with TV presenter Ben Fogle in Chay Blyth's Atlantic Yachting Race.

He will hope to finish Saturday's race quickly as he has plans for the afternoon.

"I've got tickets to the England-Australia match, but I'm going to go anyway, just not do the hospitality beforehand," he told the Daily Telegraph.

All four members of the Great Britain coxless four that won gold at the World Championships in Gifu earlier this year take part in the 550-crew Fours race.

Pete Reed and Steve Williams race together for Leander while Alex Partridge and Andy Triggs-Hodge will be in sculling boats for Leander and Molesey respectively.