Manly Sea Eagles prop Keith Titmuss has died at the age of 20 after falling ill following a pre-season training session, the NRL side have confirmed.
Titmuss was considered one of Manly's rising stars after emerging through their junior ranks and was part of the 30-man squad for next season.
He was taken from training in Narrabeen to Northern Beaches Hospital on Monday before being transferred to Royal North Shore Hospital, where he passed away.
Manly announced the tragedy in a statement on their official website and coach Des Hasler added: "We are all devastated by this news.
"Keith was a very popular character amongst the playing group. He will be sorely missed but never forgotten by the Sea Eagles."
Titmuss scored the match-winning try for the Sea Eagles in the 2017 NYC Grand Final and was named the Manly Jersey Flegg Cup Players' Player in 2019.
The NRL side's CEO Stephen Humphreys said: "Our club sends its deepest condolences to Keith's family and friends and will provide them with all of the support they need during this difficult period.
"We are working with the NRL's Wellbeing team to offer support and counselling to our playing group and staff."
The 2021 NRL campaign is scheduled to begin on March 11.