However, they today confirmed that the former Wigan Warriors player would, after all, be playing on with them again in 2020 after signing a two-year contract.
Wakefield-born Hampshire, 24, was ever-present this season, primarily playing full-back but also filling in on the wing and at half-back.
"I'm really pleased with this two-year deal,” he said.
“Both parties are happy with how it's been done.
"I'm just looking forward to pre-season now. I'll enjoy the rest of my time off and then I'll be ripping in to get ready for 2020."
Hampshire will have a fight to retain the full-back role given Trinity have signed exciting London Broncos Alex Walker in the off-season.
But head coach Chris Chester said: "I'm really pleased we've agreed a deal with Rocky for him to remain at Trinity for the next two years.
"Rocky was good for us in 2019 and now that there's a deal in place, I'm looking forward to welcoming him back in for pre-season and seeing him in the Red, White and Blue for the next two years."