It's all happening on Saturday, where the Group 1 action comes thick and fast with barely time to reflect as Irish Champions Day interweaves with Doncaster's St Leger Festival finale.As usual, Ballydoyle feature heavily in the two marquee events of the afternoon, with two major contenders in the St Leger and the VIP Constitution River (Wootton Bassett) in the Irish Champion, but it is fair to say that the vibes surrounding the operation's main actors on Saturday are mixed. Since the latter mastered the Eclipse in early July, the stable has sent out just three winners at the highest level and what for most others would represent a bonanza total seems for this set-up a bit on the light side.It hasn't been for the lack of trying, with strong representation across the board throughout the rest of July and August. Suddenly, O'Brien's own world record of 28 top-level winners that looked under threat in early summer is now touch-and-go. All that said, the master of Ballydoyle has context to place on the yard's relative quiet spell which followed such a barnstorming May and June.“We were leaving a little bit for this weekend,” he explained. “Everything leads to this weekend. In five, six or seven Group 1s recently we've finished second and that happens – maybe I didn't have the horses at a high enough pitch, thinking of this weekend coming.”So, the next two days are very much the true barometer as to where the Rosegreen contingent stand as the 2026 season begins its long final act. At Leopardstown just after 5pm, we will find out if Constitution River's early exuberance at York was down to freshness or whether it was the telltale sign of a downturn in his form. In the Leger, Christmas Day (Camelot) has to prove himself all over again, with his Derby victory having come on ground that was so compromising to many of the meeting's leading protagonists.Over the past few weeks, there have still been notable highlights for O'Brien delivered by Scandinavia (Justify) and Sun Goddess (Sioux Nation). They are again integral parts of the weekend scrimmages and two of the shortest favourites over the two days heading into battle in Sunday's G1 Comer Group International Irish St Leger and G1 Moyglare Stud Stakes.Saturday's action begins in earnest with Leopardstown's Listed Ballylinch Stud Irish EBF Ingabelle Stakes, where the Willie McCreery-trained Timeless Tale (Sioux Nation) has to back up her sensational debut at Naas, shortly before Doncaster stage the G2 Champagne Stakes. Godolphin have already unleashed a game-changer at the meeting in Thursday's May Hill and look to double up with the exciting TDN Rising Star Desert Castle (Frankel) in this seven-furlong Classic pointer.Charlie Appleby has to endure an otherwise relatively quiet weekend, so Desert Castle is a key flagbearer here.“He's got a big reputation, he was very raw on his first start at Newmarket and he has come forward from that,” said Appleby. “I always feel, when you come to Doncaster with just one run, you could probably do with a little bit more experience. It's great, but there's a fair old crowd and he struggled with the crowd at Newmarket that day and had a good old look at them. It's not a negative, but that would be in the back of my mind – I just hope he's got enough experience to be able to utilise what ability he has got, because there's no doubt there's an engine there.”Other two-year-olds carrying great intrigue and the TDN Rising Star monicker over the course of the weekend racing include Ballydoyle's Darkness Falls (Camelot) in Saturday's revamped G1 HKJC World Pool Golden Fleece Stakes at Leopardstown, the stable's aforementioned Phoenix Stakes heroine Sun Goddess and Alpha (Sea The Stars) in Sunday's Moyglare and Juddmonte's Monogram (Kingman) and Moyglare's Porto Vecchio (Frankel) in the same card's G1 Goffs Vincent O'Brien National Stakes.All these key juvenile heats feature several with potential to have a say in the 2027 Classics and will need much analysis when the dust has settled. Since 2022, their assembled winner's lists include Diamond Necklace, Auguste Rodin, Benvenuto Cellini, Chaldean, Bay City Roller, Tahiyra, Fallen Angel, Lake Victoria, Precise, Al Riffa and Zavateri, which speaks volumes for their pre-eminence as genuine sighters of elite talent.Bringing a close to the 2026 Classics, the St Leger sees Aidan and Joseph in another of a series of stand-offs which have run right through the calendar since this Saturday 12 months ago when the Golden Fleece consisted only of O'Brien runners. What seemed an aberration that day can now be seen as the first part of a continuing trend and it is no surprise that the only four runners in Doncaster's feature under 16-1 come from either Rosegreen or Owning Hill.Christmas Day and Pierre Bonnard (Camelot) were brushed aside by Maltese Cross in the Great Voltigeur last month, but few would be put off by that fact as O'Brien always leaves something to work with from that York trial. Joseph's Gordon Stakes winner Enceladus (Sea The Stars) is currently favoured over both and gets the Billy Loughnane treatment, while his live outsider Highwayman (Persian King) gets the assistance of another of the season's sensations in Saffie Osborne. Britain's shortest-priced contender is the handicapper Hatteen (Lope De Vega) at around 16-1, which says a lot. He has to step up markedly to offer anything more than a sidebar about his rider Faleh Bughenaim in the race's story.The Niarchos Family, the owners of Enceladus, have spent a while without top-level success in Britain and a win in the 250th renewal of this Classic would carry extra weight.“It would mean so much to the family to see these colours successful again,” racing manager Aurelien Voileau explained. “The family haven't won a Group 1 for five years now so winning here, in a Classic and a legend of a race with 250 years of history, would be a very exciting moment.”He added, “Joseph is very happy with the colt and he is in good form. He just put the cheekpieces on for the first time to make sure that he stays sharp for the entire distance. It is the first time over this trip and it will be interesting to see how he handles that. Joseph is quite happy to go to a mile and six furlongs on Saturday as a first step, but he would also be very happy to come back in distance in the future.”Aidan O'Brien said of his duo, “The whole team has wanted Christmas Day to stay in the Classics and to go from the Derby to the Leger is very special. Very few horses have done it. He's shown he has the class to win a Derby and he had a lovely run in York as a trial where we were very happy with him. We've always liked Pierre Bonnard a lot and he's a very classy horse. He finished second in York, but we've always thought the world of him and he ran very well. We think the Leger trip will suit him – we don't believe we've seen the best of him yet.”Later in the afternoon, Leopardstown takes over with the G1 Coolmore America Justify Matron Stakes, where Juddmonte's Falmouth and Rothschild heroine Blue Bolt (Blue Point) is met by Precise (Starspangledbanner) for the third time. Coincidentally, their clash serves as a warm-up for the main event and the showdown between the former's Item (Frankel) and Constitution River in a tantalising sequel to the Juddmonte International.Aidan O'Brien is taking the positives from Constitution River's effort on the Knavesmire.“Anything that went with him at York finished out the back, so I'd say that was a very good run considering,” he said. “It was very unusual that he was able to be that aggressive and go that early and still finish where he did, but the acid test is the next day and we're just hoping we can put it right.”Item has grown up fast this term, looking smart in the Dante and the York Stakes without completely igniting the imagination, so what he did last month on reflection looks even more impressive. By no means granted a smooth trip there, he was helped by the strong pace laid on and that looks guaranteed again as long as Lambourn (Australia) is sent forward. Leopardstown's uphill finish also promises to bring out more and this colt gives the impression he is still just a work in progress.“When you get stopped in your run inside the final furlong and a half in a Group 1, not many horses get going again and get back up to win, so that in itself was a good performance,” Barry Mahon said as Juddmonte prepare to stake a major claim on Irish Champions Weekend. “We're looking forward to it. It will be a tough race but an exciting one, hopefully.”Of Blue Bolt, he added, “The track shouldn't be a problem and the ground hopefully won't be a problem. I think Colin was keen on this race from a long way back, so hopefully she can turn up again.”Gaining new credibility, if it were needed, in the Juddmonte International, Ed Walker's beloved Almaqam (Lope De Vega) goes again and his battle-hardened profile is a bonus in what is sure to be a war of attrition. His outside draw isn't such a help and he will need all of his savvy to get into a challenging spot, while Donnacha has the opportunity to upstage both dad and big bro with the live contender A Boy Named Susie (Starspangledbanner). He might be fresher than most but, if he comes up short, it may only be a case of delayed celebration with the stable having the July Cup hero Comanche Brave (Wootton Bassett) in Sunday's G1 Flying Five.Whatever occurs on Saturday, the following day's feature Irish St Leger should provide the O'Briens with more glory, with William Haggas responsible for the sole opposition in the form of the outsider Arabian Force (Lope De Vega). If Scandinavia comes unstuck, there is always Jan Brueghel (Galileo) to take advantage or even JP McManus's Curragh specialist Trustyourinstinct (Churchill {Ire}).In total, of the 109 runners in the stakes races across Irish Champions Weekend, the O'Briens have a representation of 49 and account for 33 out of the 60 contesting the non-sprint Group 1s and two-year-old stakes contests. Along with six in the Leger, including the three main market leaders, Joseph also has the long odds-on favourite and Lowther runner-up Star Of State (State Of Rest) for Sunday's Tattersalls Ireland Super Auction Sales Stakes at the Curragh. While it will not all go their way, chances are it will be close to a benefit for Aidan, Joseph and Donnacha on the weekend that perhaps matters most to them all.The post ‘Everything Leads To This Weekend’ – Pressure Is On For O’Brien appeared first on TDN | Thoroughbred Daily News | Horse Racing News, Results and Video | Thoroughbred Breeding and Auctions.