The change in rules will also apply to other tournaments organised by the body following the commencement of the Copa America, which runs from June 20th to July 14th and will be held in the United States.
"In addition to the five changes per team authorized by the regulations, a potential sixth will be added to take care of the health of the players," CONMEBOL said in a statement.
"This is an extra substitution in the event of a suspected head injury or concussion. To do so, the main referee or the fourth official must be informed and a pink card will be used."
Several head injury charities have called for the use of concussion substitutions in football, with the International Football Association Board (IFAB) enshrining them in football's laws in March, but leaving it open to organisers of individual competitions to implement.
