On Wednesday, for one day only, I become a jockey once again. I haven't missed being a jockey, and I would be hugely exaggerating the truth if I said I'm wildly excited about my brief comeback, but I'm doing it for the very best of causes.

Jack Berry asked me some time ago to take part in the Leger Legends race at Doncaster. He asked AP to ride in it last year. AP found it impossible to refuse Jack - and, indeed, he didn't want to refuse. When Jack popped me the question I felt exactly the same. The race raises serious money for the Injured Jockeys Fund, a charity for which Jack has done so much. The least I can do is give up some of my time and help to boost the IJF coffers.

The time, however, is the big problem. Training racehorses on any sort of meaningful scale is an all-consuming activity. There really isn't enough time in the day. I'm dreading the journey up to Yorkshire, simply because I'm mad busy and there are so many other things I should be doing instead of driving to and from Doncaster. With the sales season about to go into overdrive I want to spend as much time at home as I possibly can.

But, as I said, this is for the IJF and for Jack, so my answer had to be a yes. I'm also sure that, although not excited right now, come the big day the old instincts will take over and I'll become extremely keen to win.

I reckon I'm still more than physically capable of doing exactly that. I continue to ride out - as I've said before, it would be stupid not to make the most of an advantage I might have over other trainers - but I haven't been riding out any more just because this race has been moving ever closer.

When I was eight and a half stone, fitness was never an issue for me. I once broke a leg and was off for six months but didn't have to do anything out of the ordinary to come back fit. I was just naturally like that. If I ran to catch a bus I would have been breathless. Put me on a horse and I've always been fine. In the Donny weighing room I'll be around 10st 4lb in silks. I certainly won't have to ride in my one-pound saddle - although I do wonder where I'm going to find riding gear that will fit me!

Until declarations are made on Monday I have no idea which horse I'll be riding in the race, but I do know who I'll be riding against. It's quite a cast.

The only Derby-winning rider in the field will be Joseph O'Brien. He is bound to be hard to beat as this will be the first time in his life he has ridden in a race when not hungry.

Another multiple Group 1 winner taking part is George Duffield. I definitely don't want to get into a close finish with him as he would probably still beat me. I also don't want to walk into the paddock with Gary Bardwell, just in case I get mistaken for a giraffe. Another thing I'm hoping is Tony Culhane doesn't bring one of his packs of playing cards into the weighing room. For the rest of us that could prove very costly.

Dale Gibson will no doubt have a moan that none of the horses are allowed to run off 8st - or maybe even 7st10lb. As a former jump jockey Luke Harvey won't have seen that sort of weight for a long time. My hope for him is that as this is a Flat handicap he won't have to call any cabs. If he does have any problems he'll be able to have a chat with Gay Kelleway who, no doubt, will be able to give us all some riding lessons down at the start.

Goodwood has always been a special place for me and it was lovely to receive such a positive reception after Paco's Angel, one of the real stars of our stable, won Tuesday's £20,000 fillies' nursery at the track under Shane Kelly.

We had trained her specifically for the Newmarket nursery she ran in on her previous start. I had thought it was a tailor-made opportunity, as in most Newmarket races they go fast, especially in handicaps. That would have suited her to perfection.

Unfortunately, she was drawn out on the flank in stall two. Shane Kelly knows I like to see my horses covered up, so he had to switch in to get that cover in what turned out to be a slowly-run race in which the winner got a soft lead and made most of the running. We came out of the pack and finished fast for second.

After that we decided to wait for the next valuable fillies' nursery, which was Tuesday's event at Goodwood. The key thing this time was they went hard up front. That made it look as though she was quickening inside the final furlong but, in reality, it was more a case of the leaders coming back to her. I do think she will show a turn of foot when stepping up to seven furlongs but to win over six she needs those in front of her to race hard.

The owners have been a massive help as they have allowed me to patient. The day Mrs Danvers beat us at Lingfield we came off the stands with sad faces, but we obviously didn't realise how a good a horse we had chased home. The owners then allowed me to run her on soft ground at Windsor, where I needed to get her handicap mark. She hated the conditions but still won and ended up with a favourable rating. As I've said before, it's important not to be afraid of losing. That night at Windsor was a good example of that.

The obvious thing now is to try to get some black type for Paco's Angel. She has a very good pedigree with her mother being a sister of Grand Lodge, so a Listed or Group placing, or even a win, would be priceless. We'll head up to Ayr for the Firth of Clyde, which is generally a true-run race.

Goodwood on Tuesday wasn't all good news. We had expected Nathania to break her maiden tag at the second attempt and were gutted when she finished only fourth. At first we blamed the slow early gallop. However, we found her to be lame the next morning and it looks as though she has a small fracture. That will keep her off for six weeks, so we'll now look forward to next year with her.

It's disappointing for the six of us who own her. One member of that sextet is none other than Sir Anthony McCoy, who came along to Goodwood, where I unveiled him as my new assistant. He is also my trickiest owner. It's still nice to have him as part of the team, though.

David Wachman will be a significant loss to the training ranks.

Not only is he an excellent trainer - witness the brilliant job he did with Legatissimo - he is also a thoroughly nice man.

The sport will miss him but I respect anyone who takes the brave decision to walk away. I send my best wishes to David and his family.