Harlequins have signed Australian forwards Shane Rodney and Antonio Kaufusi on three-year deals.
Second row Rodney, 28, has joined from Manly Sea Eagles and played 125 games in the National Rugby League.
Australia international Prop Kaufusi, 26, has been signed from Newcastle Knights, having previously played for Melbourne Storm and Queensland Cowboys.
The pair's arrival brings the total of new signings for next season to five for struggling Quins.
"Shane has a lot of games under his belt including a Grand Final win," said Harlequins coach Rob Powell.
"He is a decent defender and will provide good strike on an edge.
"Antonio has played some of the best football of his career this season - the sort of form that saw him play for Australia a few years ago.
"He is a big, explosive prop and will add a lot to our pack."
Quins currently stand 12th in Super League XVI, having long since fallen away after a cracking start under Powell which saw them win four of their opening five games to go top of the table.
But they have since won just once in 19 league games, having never recovered from an 82-0 annhilation at Warrington - and are still at risk of finishing bottom, just three points clear of Crusaders and Wakefield.