Michael Phelps back at the pool

Sydney - Michael Phelps has been working out with his former coach but is still not ready to announce a much-speculated comeback to swimming in time for the Rio Olympics.

Bob Bowman said on Sunday that Phelps has been swimming occasionally with the North Baltimore Aquatic Club, but mainly as a means of getting into better shape.

Phelps and Bowman remain close friends and business partners.

After winning 18 gold and 22 Olympic medals overall, Phelps announced his retirement from swimming after the 2012 London Games.

Initially adamant he would never compete again, Phelps softened his stance this past summer after reports began swirling of an imminent comeback. He said during the world championships in Barcelona that he doesn't "know what's going to happen in the future."