The change of medical opinion from Michel D'Hooghe was a key step before FIFA's law-making body could approve two scarf designs when it meets in Zurich next week.
"The problems I had (with scarves) were medical, and I don't have those problems anymore," D'Hooghe told The Associated Press.
The panel, known as IFAB, asked in March for further medical advice on whether new designs were safe for women players to wear. Headscarves were banned from FIFA competitions for safety reasons in 2007.
Last month, D'Hooghe said his committee's tests suggested scarves "represented a danger" to players who could sustain head and neck injuries, or overheat.
That drew an angry response from his FIFA executive committee colleague, Prince Ali of Jordan, who has led a year-long campaign seeking respect for Islamic cultural tradition, and creating more opportunities for women to play, by overturning the ban.
Prince Ali said he was "quite shocked," and produced medical research which challenged FIFA's position.
On Friday, D'Hooghe said he would no longer object to the designs after "more discussions" in recent weeks.
"There is no risk of strangulation. I was asked for a medical opinion, and the discussions I had were purely medical," said the Belgian doctor, who did not elaborate on what swayed his opinion.
IFAB could accept one or both designs — one from the Netherlands, which uses quick-release velcro fasteners, and a Canadian scarf fixed with light magnets.
However, D'Hooghe cautioned that the scarves must still abide by football's rules regarding players' equipment.
"Those aspects are the uniformity of players' equipment and the idea of religious and political statements," D'Hooghe said. "That is a discussion for other people."
Law 4 of football states that "basic compulsory equipment must not have any political, religious or personal statements."
Still, Prince Ali's campaign has been backed by the United Nations, the Nobel Prize Committee and the global players' union, FIFPro.
The IFAB panel which will decide the issue next Thursday includes the four British football associations, which have one vote each, and FIFA which has a four-vote bloc. Six votes are needed to change a rule.
IFAB also will vote on whether to approve two goal-line technology systems, plus UEFA's five-officials system which uses additional assistants beside each goal.