FIFPro said that UEFA's match officials failed to act after Toure was racially abused during the Champions League clash away to CSKA Moscow on Wednesday.
"We're very disappointed that a clear agreed protocol which is designed to deal with these situations was not implemented," said Bobby Barnes, head of FIFPro's Europe division.
UEFA issued guidelines in July 2009 giving match officials the power to stop and abandon games in case of serious incident.
They outlined a three-step procedure for abandoning games. It said that the referee should first stop the match and ask for announcements to be made over the public address system.
The second step would be to suspend the match for a given period of time and, finally, abandon it.
In March, UEFA issued a resolution calling on referees to follow those guidelines.
No match, however, has ever been abandoned in European club competition since the guidelines were introduced.
Barnes said that UEFA wanted to counter the possibility that players could simply walk off in protest.
"These guidelines were brought into place because players were feeling that if this doesn't stop, then they would take the step themselves to walk off," he told Reuters during a FIFPro general assembly.
"It's very difficult for us as a players' association to tell players not to take the matter into their own hands if the procedures are not being followed.
"If the referee is made aware of such chanting, he should approach the stadium safety officer and there should be an announcement over the stadium loudspeaker that if it persists, the players would be taken off.
"That is what should have happened, sadly it didn't happen."
"It's disappointing," he added. "You have procedures and UEFA have been quite outspoken in terms of their new zero tolerance, there have been harsh sanctions advertised for player on player.
"We would like to see a similar harsh sanction applied to those who come to football grounds and think they have the right to abuse players because of the colour of their skin.
"I was particularly disappointed with the official statement from CSKA who said it didn't seem to be much to make a fuss about and they couldn't hear anything."
UEFA regulations currently impose partial stadium closures for a first offence but former West Ham player Barnes suggested a complete stadium closure would be more effective.
"We played in front of a real empty stadium (in the Cup Winners Cup against Castilla), there is a difference in the dynamic and totally takes away your home advantage, so I think something like that would be an effective deterrent," he said.
"It's so sad that here we are in 2013 talking about racism."