CONMEBOL President Alejandro Dominguez has said he was surprised that global football governing body FIFA decided to allow up to five substitutions per match following the coronavirus pandemic.
FIFA has allowed teams to have up to five substitutions per game, instead of three that was there before, as a temporary measure to help cope with potential fixture congestion.
"We are taken by surprise by this measure, which was not consulted with our confederation," the head of the South American Football Confederation said on Twitter.
"CONMEBOL will convene a panel of experts to analyse it and present its conclusions to the board, which will decide whether to adopt it in South American tournaments."
Earlier on Friday, FIFA said that world football rule-making body IFAB approved the change after receiving a proposal from FIFA that sought to protect the health of players amid the pandemic.
"The temporary amendment comes into force with immediate effect, and has been made as matches may be played in a condensed period in different weather conditions, both of which could have impacts on player welfare," FIFA statement read.
The changes come as football leagues around the world prepare to restart after almost two months of inactivity caused by the global pandemic. South Korea's K-League resumed on Friday and Germany's Bundesliga will restart on May 16.
However, South America's top leagues are yet to determine a return date.