Sønderjyske has confirmed that Osaze De Rosario is joining on loan from Seattle Sounders FC, in a deal that it is stated includes a purchase option. The club's sporting director, Casper Daather, commented on Osaze De Rosario's qualities and his expected contribution to the team.

Sønderjyske Fodbold is loaning 25-year-old Guyanese-Canadian striker Osaze De Rosario on a loan deal. Haderslev-klubben is loaning Osaze De Rosario from Seattle Sounders, subject to the completion of the mandatory medical check and final details. Journalist Nico Moreno reports that Seattle Sounders is finalizing the agreement with Sønderjyske. De Rosario joined Seattle in May 2025 and is under contract until June 2029. The forward has a current Transfermarkt market value of €800k, has scored 10 goals in 11 caps for Guyana, and has 2 goals in 18 Major League Soccer appearances this season.