The 18-year-old has joined on a contract that runs until June 2025 and is the son of former Danish goalkeeper Brian Jensen who had an impressive career that included a stint at Crawley Town.
Sebastian has previously played for Everton under-18s, Stoke City under-18s, and Bolton Wanderers under-18s. He now joins a long list of goalkeepers including Killian Cahill, Hugo Fisher, Steven Hall and Lorenz Ferdinand who are set to bring a bright future to the Seagulls.
Under-21s head coach Shannon Ruth spoke on the move and expressed his excitement at bringing in such a talented young goalkeeper.
“We’re looking forward to continuing to work with Seb after a successful period on trial.
“He adds really good competition to our goalkeeping group. We’re excited to see him develop over the course of the season.”