According to rules, players who have qualified for an IPL side and another team will have to choose the former in the Champions League T20 to be held in India next month.
Watson and Mitchell Johnson played for Rajasthan Royals and Mumbai Indians respectively in the IPL besides being members of Big Bash team Brisbane Heat which has also qualified for the Champions Trophy.
Watson's Champions League commitments caused great angst last year, when CA upset the Sydney Sixers by insisting he return to prepare for the home season. He ended up breaking down before the first Test against South Africa and endured a second injury-affected summer in succession, the report said.
Before the first Ashes Test starts in Brisbane on November 21, Australia play six one-day internationals and two T20s in England, and seven one-day games and a T20 in India. In between is the added complication of the Champions League.
CA's resolve will also be tested when it picks the squad for the limited-overs tour of India from October 10 to November 2.
The temptation will be to rest Test stars such as captain Michael Clarke and Watson before the Ashes, but that presumably would not go down well with the Board of Control for Cricket in India, the report said.