"The Sea Eagles are working closely with the NRL, the RLPA, and the players' respective managers George Mimis (Stewart) and Gavin Orr (Matai) to give the players a dignified and respectful exit from their brilliant careers," the club said in a statement on Friday.
"Both players have been unable to train in preparation for the 2017 NRL season as a result of surgery at the end of 2016 and the inability to receive medical clearance to train.
"Manly Sea Eagles are working with the management of both players to give them the farewell they deserve in front of their thousands of adoring fans."
Both players were a part of Manly's premiership teams in 2008 and 2011, and have scored a combined 254 tries in 462 games as one-club players.
Matai has not played for Manly since round nine last year, while Stewart missed the final 10 weeks of the 2016 season with his knee injury.
-AAP