Ahmadzai and his selection panel colleagues effected a leadership revamp last month, naming different captains for different formats, which resulted in Gulbadin Naib replacing Asghar Afghan as their ODI skipper.
Senior players including spinner Rashid Khan, who has been named Afghanistan's Twenty20 captain, took to social media to criticise the overhaul while many others questioned its timing.
Ahmadzai said it was the right time to blood a new captain even though Asghar remains part of their World Cup squad.
"At this point, Afghanistan cannot win the World Cup with Asghar or with Gulbadan (as the captain). But it's a great opportunity to promote a young captain... we have to go for the transition phase," he told a news conference in New Delhi.
He said dissenting senior players like Rashid and Mohammed Nabi have since been taken into confidence and it was now a united dressing room.
"That was their personal opinion... we handled it very professionally and now they are happy," Ahmadzai said.
"Gulbadan has said he'll make use of Asghar's experience. There is nothing wrong with the team environment. Changes do happen, like Sri Lanka did with their captaincy.
"The top management wanted a change in captaincy. There must have been reasons why we took such a decision - keeping the betterment of the team in mind rather than individuals. We are hopeful of good results."
Afghanistan made their World Cup debut in Australia four years ago, beating Scotland but crashing out from the opening round but have scripted a fairytale rise since then.
They beat Sri Lanka and Bangladesh at the 2018 Asia Cup and played a thrilling tie with a depleted India and became the 12th test playing nation last year.
"In 2015, there was no Rashid or Mujeeb. So we are expecting a lot this year and looking for semi-finals in the World Cup," he said.
"We have identified teams we can beat but obviously I can't tell you which teams."
Ahmadzai said fit-again paceman Hamid Hassan's return to the squad would significantly improve their pace attack which would complement their world class spin attack spearheaded by Rashid.
"I don't accept that our batting is weak, but we need some order there," Ahmadzai said.
"With Dawlat Zadran and Hamid Hassan, we have a good fast bowling attack."
Afghanistan begin their World Cup campaign against holders Australia in Bristol on June 1.
(Reporting by Amlan Chakraborty in New Delhi; editing by Sudipto Ganguly)
