The International Hockey Federation (FIH) have confirmed the new competition, due to launch in 2019, will retain its nine-team structure.

Spain and Belgium both took part in the first Hockey Pro League Workshop at the FIH's headquarters in Lausanne from July 17 to 19.

Scheduling, league management structure and a number of league operational matters were among the issues discussed at the workshop, which the FIH claim was "an extremely positive and constructive session".

Spain's men and Belgium's women were approved as the first reserves following an oversubscribed application process in June.

After India withdrew, the inclusion of Spain and Belgium was given the green light by the FIH Executive Board following a recommendation from the worldwide governing body's Event Portfolio Implementation Panel.

Belgium will join Argentina, Australia, China, England/Great Britain, Germany, Netherlands, New Zealand and the United States in the women's tournament.

Spain will go up against Argentina, Australia, Belgium, England/Great Britain, Germany, Netherlands, New Zealand and Pakistan in the men's Pro League.

The two countries were able to join the league, which replaces the Champions Trophy and Hockey World League Semi-Final and Final events as part of an FIH overhaul of their competition portfolio.

Hockey India denied their withdrawal was linked to a move to file a complaint to the FIH of match-fixing against Pakistan after a 7-1 victory over their bitter rivals at the World Hockey League Semi-Final last month in London.

The organisation instead claimed they had withdrawn from the Pro League because of the the poor ranking of the women's team but a detailed explanation was not given.

According to the Hindustan Times, Indian officials believe that their women's chances of qualifying for the Tokyo Olympics in 2020 would be better served by competing in the World League.

Failing to take part in the Pro League event significantly reduces their opportunities to play the world's best sides, however.

The Hindu reported that Hockey India had written to FIH chief executive Jason McCracken raising alleged match-fixing attempts by Pakistan during the 7-1 victory on June 18.

The match was also notable for FIH President Narinder Batra being forced to apologise afterwards for a series of abusive posts about Pakistan on Facebook.

Hockey India also criticised the Yorkshire police decision to question former captain Sardar Singh with regards to a four-year sexual assault case on June 19.

This had followed a complaint in relation to an incident which had allegedly taken place in 2013.