The Scotland international, who played seven games in League One for South Yorkshire neighbours Doncaster last season, has penned a one-year deal.
Director of rugby Mark Aston has recently spoken of his desire to add an experienced forward to add the gloss to his recruitment drive, with Mariano’s arrival certainly ticking the final box.
The 32-year-old has previously starred for Hull KR, Wakefield, Castleford and Featherstone in a career which has seen him play at Super League, Championship and League One level.
Injury has restricted Mariano to just 23 appearances in his last two seasons with the Dons, but Aston says he is fit and ready for the 2020 campaign.
“We are highly delighted to secure Frankie’s signature,” said Aston.
“We were missing another forward so it’s great to get this deal across the line.
“He has had some rotten luck with injuries over the past two seasons, but he is fresh and raring to go.
“He’s hungry to fight for a place in the team and get back to the great form he has shown in the past.
“He is the type of character we need in this team and I look forward to working with him.”
Mariano is the Eagles’ seventh new arrival, taking Aston’s numbers to 23 for next season.
Meanwhile, the early bird deadline for 2020 season memberships is today (Monday 11th November). Prices are set to go up in all age categories from tomorrow.