Shaun Lunt has rejoined Leeds from Hull KR, with Matt Parcell moving in the opposite direction, while the Rhinos have also signed Robert Lui.
Lunt joined Hull KR in 2015 but has struggled for game time this season, making just seven appearances. His deal runs until the end of the current campaign with the possibility of an extension.
Meanwhile, former Brisbane and Manly forward Parcell has also moved until the conclusion of the 2019 campaign, as both clubs rejig their squads in the battle against relegation.
Rhinos director of rugby Kevin Sinfield said of Lunt: "He is an outstanding professional who knows our club well. He had a huge impact on the squad during his first spell here."
Lunt could make his debut in the Rhinos' clash with Catalans Dragons on Sunday, while Parcell has gone straight into the Rovers squad for Thursday's derby against arch-rivals Hull FC, live on Sky Sports
Leeds have also signed Salford stand-off Robert Lui for an undisclosed fee in an attempt to bolster their squad.
His move was made possible on the overseas quota and under the salary cap by allowing hooker Matt Parcell to leave.
Leeds had been heavily linked with a move for half-back Lui as they look to rescue a dismal season. The Rhinos, who sacked David Furner as coach last month, are 11th in the table, level on points with bottom side Hull KR.
Lui, who previously played for Wests Tigers and North Queensland Cowboys, moves after four seasons at Salford, during which time he has scored 31 tries. He has signed at Headingley until the end of the 2021 season.
Sinfield added: "We are pleased to have brought a half-back of Robert's experience into our squad.
"He has proven his quality in Super League over the last four seasons and I know the players are looking forward to working with him."
Lui, who could make his debut against Catalans Dragons on Sunday, said: "It is great to be here. I can't wait to pull on the Leeds jersey and run out at Emerald Headingley."