Lance Armstrong's return to competitive sport this weekend will be against veteran swimmers, a Texas newspaper reported.
Most competitors in the US Masters Swimming event entered by Armstrong will be older than the 41-year-old cyclist, the Austin American-Statesman said.
Armstrong is banned for life from all competitions that adhere to world anti-doping codes, but is allowed to take part in the low-profile Austin swimming event.
US Masters Swimming executive director Rob Butcher said nobody had raised formal objections to Armstrong competing.
Butcher added: "The purpose of our organisation is to encourage adults to swim."
More top news
Vincent Kompany claims it is "unacceptable" Man City had no fans at their Champions League tie at CSKA while the home side apparently did
Teenagers are being tricked into sending inappropriate photographs through social media, police say.
June and Barry Steenkamp tell Good Morning Britain they accept the judge's decision but still do not believe Pistorius' version of events.