Brisbane Broncos star fullback Reece Walsh has reportedly agreed to terms on a new deal with the club.

The fullback, who is currently out injured after a head clash with Penrith Panthers outside back Taylan May last weekend, isn't off-contract until the end of next year, but is set to take himself off the open market early.

In what will be a major retention coup for the Broncos, News Corp are reporting Walsh will re-sign on a $5.5 million dollar deal over five seasons, tying him in at the club until at least the end of 2029.

The deal will make Walsh the highest-paid player in Broncos' history, and the NRL's youngest player on at least a million dollars per season once it begins.

Walsh has been the key retention target for the Red Hill-based club, with the Broncos understandably keen to ensure he is off the open market before he has the ability to talk with rival clubs from November 1.

It was previously tipped the Broncos may have had some salary cap issues in retaining Walsh given they have already locked in Ezra Mam on a long-term deal and have other big contracts floating around the club for the likes of Payne Haas and Patrick Carrigan.

Walsh re-signing will likely leave the Broncos with some tough questions around the remainder of their roster, however, the off-season departures of Herbie Farnworth, Thomas Flegler (both Dolphins) and Kurt Capewell to the New Zealand Warriors have helped to ease some of the strain.

It's tipped Walsh may have fielded as much as $1.3 million per season on the open market from rival clubs desperate to secure the 21-year-old.

The young gun played State of Origin last year and will be again in the mix for the Maroons this year on the back of his form at the Broncos.