Forbes is one of the most successful players to ever pull on the sevens black jersey having made his debut for the team in 2006.
"I've been captain pretty much since making the team so this move might allow me a bit of freedom to really enjoy what will probably be my last year of international sevens and to go out and play as one of the boys.
"I never played rugby to be the captain but the privilege of leading this team has been a huge honour. Not having (c) after my name isn't the end of the world because I'm still living the dream, doing what I love."
Coach Gordon Tietjens said he would name a successor to Forbes shortly when the initial squad for the 2015/16 season was named later this month.
"I complement DJ on the big decision he has made and wanting to solely focus on getting to the Olympics. He wants to overcome his injuries and doesn't want the pressure of captaincy and I respect that.
"It's going to be very competitive to win selection and he knows that. We both feel this decision will allow him the space to focus on overcoming his injuries and getting in the right shape. This will give him the best opportunity to make the team.
"He has been wonderful captain and we will still rely on his experience and leadership skills to help the new captain. He still has much to offer the team.
"DJ always led by the way he played; he is an inspirational figure and very much the face of sevens and the team. Our successes over the years owe much to his skills as a player and leader."