The Airlie Birds yesterday paid a fee to League One club Doncaster to secure the talented scrum-half with immediate effect.
Harris, 21, has signed a two-and-a-half year deal with the club he supported as a boy and goes straight into their 19-man squad for Sunday’s game in Newcastle.
He came through the City of Hull Academy system, scoring 15 tries in 18 games in 2016, as well as signing professional terms with the Robins.
But he spent the majority of last season on loan at York City Knights and turned down a new deal with promoted Hull KR to join Hull’s dual-registration partners Doncaster ahead of this term.
However, with both FC’s starting half-backs – Marc Sneyd and Albert Kelly – and their two stand-ins, Carlos Tuimavave and Jordan Abdull, all sidelined with lengthy injuries, it was clear Lee Radford needed to move.
“Hull have a few injuries in my position and that gives me a good opportunity to come in and show what I can do,” said Harris, who made his senior debut with Rovers last year.
“I’m ready to have my shot at Super League.
“All the young lads wait for opportunities like this.
“Nobody likes to see players get injured but the one positive it brings is the chance for players to come through and have a crack.
“There’s a chance I could be involved this Sunday against my old side. It’s a bit of a baptism of fire but it’s a chance I’m really excited for.”
Harris actually played for Hull in their pre-season friendly against Hull KR as part of the dual-registration agreement with Doncaster.
As part of this deal, the player will be able to rejoin Doncaster later in 2018 when needed.
Radford said: “Liam can do a really good job for us over the coming weeks. He’s a confident and skilful player who does a lot of talking on the field.
“He has trained with us before and knows the players. Having him being able to jump straight in is really helpful.
“I’ve watched their games most weeks so I’m aware of his form. I think he’ll do well this weekend.
“He’s a controlling half and he can get a team around the field.”
Wakefield Trinity will welcome back Tyler Randell, Craig Huby and Reece Lyne into their 17-man squad for Sunday’s game against Huddersfield Giants.