St Helens have confirmed the signing of prop Matthew Haggarty from Dewsbury on a three-year contract.
The 24-year-old has been loaned back to the Championship club ahead of their opening game of the season against Sheffield Eagles.
"We're delighted to have agreed terms with Matthew. He is a forward of promise and we look forward to seeing him develop within our system," chief executive Mike Rush told Saints' official website.
"We like what we see and we are pleased to have reached an agreement with the Rams. They have been very professional in our dealings. Matthew will train for us during the week and play with Dewsbury, where we will monitor his progress."
St Helens got the defence of their Super League title underway on Friday with a 18-7 win at home to Catalans Dragons.
