Despite having two Stobart Flat Jockeys Championships in the locker – with a third on its way – chances for the 37-year-old to shine in such contests are not as forthcoming as might be expected for a man that has ridden more than 1,500 domestic winners.
And the father of two is conscious of making the most of just such an opportunity on the Mark Johnston-trained three-year-old in his pursuit of a first British Classic success.
De Sousa said: “He is a nice horse to have a ride on and I’m just very pleased to be on the horse.
“In Classic races if you are not associated with the big yards like John Gosden, Sir Michael Stoute and Aidan O’Brien it is hard to get these big horses that can take you to the top.
“This makes rides like this 100 per cent more important. It’s nice to ride winners day in, day out, but it would be nice to get a top horse to take me to the top level.
“It has been something I’ve been working for, it’s not quite happened but it will be a great achievement if this can happen and another great winner to have on my CV.”
Although beaten at odds-on last time out at Goodwood, Dee Ex Bee, a son of Farhh, has run some fine races in defeat this season, most notably when second to Masar in the Investec Derby.
Dee Ex Bee finishes runner-up in the Derby.
With a step up in trip to a mile and three-quarters and slower ground conditions expected to be in favour of his mount, De Sousa – who recently passed the 150-winner mark for the year – is optimistic that more improvement can be found.
He said: “The ground was not in his favour at Goodwood and I’m sure he is a better horse than that.
“This ground will help him out. I’d like to think that’s his trip. He is a horse that was really strong in the finish of the Derby.
“He got there and he felt like a stayer and I felt a mile and six was what he was looking for.
“Of course we have not seen the Derby winner (Masar) come out yet, but Roaring Lion has proven he is a good horse and we just finished in front of him in the Derby – it might be that he didn’t stay, but if we run to that class then that gives him a chance.
“It is a tough race on Saturday and we don’t go there as a 2-1 shot, but he has got a good chance of finishing in the first three.”
Since arriving from Brazil, there have been few trainers that have offered De Sousa as much support as Middleham-based Johnston and with that in mind, a first victory in the world’s oldest Classic would make it all the more special.
De Sousa said: “It would be my dream come true to win this for Mark Johnston.
“He he has been very good to me for years and this would be a good way to say ‘thank you’ for that support. I will be giving him the best ride I can.
“Kew Gardens is probably the main horse to beat, but it’s an open race, a case of the horse that stays will win.
“The horse I ride has got a great chance to stay, I’m not saying we are going to win, but we go there with a chance.”
The Group One-winning rider is well clear in the jockeys’ title race this season, but while he is keeping a level head on that front, he acknowledges Classic success on Town Moor in the latest leg of the Qipco British Champions Series would make title number three that bit sweeter.
He added: “It will be nice to have another champion jockey title on the CV, but it’s not finished yet and there is still a long way to go.
“It’s not cemented yet and you can never be sure of it until it’s over, as anything can happen.
“The St Leger is the last Classic of the year so to have a ride in it is great, but if I can ride the winner even better.
“Winning it would be one of the highlights of the season for me and if I become champion jockey again it would make that achievement greater.”