Australia got encouragement to start bowling again this week with injured pace bowler Josh Hazlewood and Mitchell Starc and fit to defend their World Cup.
Hazlewood has been sidelined from January with a back injury, while Stark pulled out "enough" muscle tears during last month's Twenty20 and one-day tour of Australia.
The pair's return to the Nets has taken place before the time when Zaheer returned to home with a one-day series against Zaheer Khan, with this shoulder.
Hazlewood said in a Cricket Australia podcast, "When the team is announced, I will probably be 65-70 percent and from that day I will be ready to play ODI cricket for four or five weeks."
Australia's World Cup team should be named by April 23, with the tournaments starting in England from May 30.
The team will have a training camp in Brisbane in the beginning of May and expect to play some warm-up games against New Zealand before going to UK.
Hezlewood said, "I do not think I'll be fit for those people, but one-day warm-up games in England will be right for me."
Stark, the 2015 World Cup player of the tournament, is performing well in his return after injury during the second Test against Sri Lanka in early February 2015.
Hejelwood said, "He (Stark) looks fine, he started bowling this week."
"He is not taking my biggest break, so he will not be late in getting up and running. He is going in the right direction."
