The new NBA season will start next week, on Dec. 22, with the regular season wrapping up on May 16 before the playoffs between May 22 and July 22.
The Tokyo Olympics, which were postponed by a year to 2021 due to the COVID-19 pandemic, kick off on July 23, with the basketball preliminaries starting two days later.
"Looking at the late finish of the Orlando bubble (last season's playoffs) and the following season, we had requested an in-depth discussion with the NBA and the NBA players association," Zagklis said.
"We explained what the repercussions are on the Olympic qualifying tournaments and the Olympic Games," he told a virtual round table.
He said the Olympic qualifying tournaments had been delayed by a week to late June following talks with the IOC to accommodate the late NBA season.
"I believe this means we will have at the Olympic qualifiers more than 85 percent of the NBA players available and all teams will have finished in time for the Games," he said.
"I think we will have the best players available at the Olympic Games and FIBA are satisfied with that."
Since professional players were allowed to compete at the Olympics, beginning with the 1992 Games in Barcelona, the United States have won six out of seven gold medals with star-studded squads made up primarily of NBA players.
With more than 100 international players in the NBA, other countries also have concerns over availability for Olympic qualifiers and the Games themselves.