Leopardstown will have to pass an early morning inspection if their Guineas trials card is to go ahead.
The Saturday programme at Bellewstown fell foul of the weather. Race-goers must wait until early Sunday morning to find out if the Dublin track suffers a similar fate.
"Following a further 4mm of rain at Leopardstown this morning which brings the total rainfall to 24mm since declarations yesterday, there will be a 7.30am precautionary inspection tomorrow ahead of the fixture scheduled to take place. The ground is currently heavy and fit for racing," a HRI statement read.
Lorcan Wyer, IHRB Clerk of the Course, said: "Since declarations yesterday there has been 24mm of rain at Leopardstown, 4mm of which has fallen since 7am this morning. That brings the total rainfall at Leopardstown to 35mm of rain since midweek.
"We've spoken with Met Éireann and their forecast is for potentially a further 5-6mm of rain this evening. Tomorrow is set to remain dry with some sunny spells but in light of all the recent rainfall and the potential of further rain this evening, we will hold a precautionary inspection at 7.30am on Sunday morning."
Irish Champions Weekend winner Zarinsk is among a classy field of 14 runners set to line up in the Ballylinch Stud "Priory Belle" 1,000 Guineas Trial - should the meeting get the go-ahead.
Trained by Ger Lyons, the Juddmonte-owned filly bounded clear to win the Ingabelle Stakes in September, after which connections were happy to put her away for the season.
While that victory came on soft ground, the going is expected to be far more testing this weekend, the going is officially listed as heavy.
"She ended last year on a good note winning on Champions Weekend in good style and she's wintered well, Ger is happy with her and this looks a nice starting point," said Juddmonte's Barry Mahon.
"She won with cut in the ground - but there's cut and there's what we have at the minute. We've had a lot of rain recently, so you wouldn't know about heavy.
"She's a very nice filly and we've been very happy with her, and she's ready to go.
"There was no temptation to run her again after Leopardstown. That was job done - she'd won her stakes race. So we put her away, as she was a very tall filly last year, and straight after the race we were happy to say that was her season done and to give her a bit of time.
"She'd had four runs, so hopefully we've a nice filly for this year."
Aidan O'Brien runs three, with Ryan Moore on Never Ending Story, who brings Group One form to the contest, having been fourth in the Moyglare and third in the Prix Marcel Boussac.
Joseph O'Brien's Madly Truly and Thornbrook, Kieran Cotter's Matilda Picotte, Dermot Weld's Tarawa and Paddy Twomey's Impact Warrior also bring strong claims to the table.
Only seven colts have been declared for the Ballylinch Stud "Red Rocks" 2,000 Guineas Trial.
Aidan O'Brien's Hans Andersen sets the standard, having finished second in the Futurity last season before slightly disappointing in the National Stakes when fifth.
Jessica Harrington runs Bold Discovery, bought by owner Marc Chan following an impressive debut win at Naas.
His first run in his new colours saw him finish a respectable third to Cairo in the Killavullan Stakes.
"He might be just a bit short of match practice but we hope he will be a nice horse this year," said Jamie McCalmont, the owner's racing manager.
"First time out he ended up on the lead and won, and I think that was a bit of a surprise, then the next time he ended up on the lead again. So the horse just lacks some racing experience and the idea on Sunday is to get him to come from behind and I think he will improve a lot from Sunday's race.
"He's a very big horse that will hopefully just get better with time, so we will take things slowly with him."
In 2016 Dermot Weld's Harzand won the PW McGrath Memorial Ballysax Stakes before winning the Derby and the O'Brien family will be hoping to repeat the trick.
Aidan O'Brien runs the Moore-ridden Alexandroupolis, winner of his only start to date, as well as Denmark and Mohawk Chief.
His eldest son, Joseph O'Brien, is represented Up And Under, while his sibling Donnacha is represented by Alder, third in a Group Two to Auguste Rodin when last seen.
