 It was revealed on 6 December 2018, that Donaldson had been handed a trial at the Leeds Rhinos ahead of the 2019 campaign.Donaldson was subsequently given a chance to "prove his worth" to new Leeds Rhinos Head Coach David Furner, in all hopes of earning a contract at the club on a permanent basis.On 8 January 2019, after a successful trial, Donaldson signed a one-year contract with the Leeds Rhinos.