Trainer Nicky Henderson had intimated that Oisin Murphy would be reunited with the 2023 Champion Hurdle winner having ridden him to his first win on the Flat at Southwell in February, but there has been a change of plan.

Rossa Ryan has received the call to ride Constitution Hill in Sunday's Gran Premio del Jockey Club in Italy.

Trainer Nicky Henderson had suggested on Sunday that Oisin Murphy would reunite with the 2023 Champion Hurdle winner, having partnered him to victory on the Flat at Southwell in February, but plans have shifted.

With substantial rainfall forecast for Italy, it appears Constitution Hill's alternative engagement in Saturday's St Simon Stakes at Newbury will remain a reserve option, with all signs pointing towards the San Siro assignment.

"It's a bit of a mad one," Ryan told Sky Sports Racing at Yarmouth on Tuesday.

"I was in Milan last weekend and Nicky rang me to see what the ground was like yesterday morning, then he rang me back yesterday evening to see if I could ride him, so it's a great opportunity.

"I literally got the phone call last night so I've never ridden him. He's popular for sure. San Siro is just like this (Yarmouth) – it's just the other way around – and I was reading between Wednesday and Thursday they are due 52mm of rain, so it will be proper soft ground.

"It looks a good race on paper and he'll have a chance. I was speaking to Oisin and he said the softer the ground the better, so we'll see."