Fabricio Coloccini was struck in the face by a coin while celebrating Papiss Cisse's opening goal for Newcastle United in the 1-1 draw at Selhurst Park last Wednesday.
Newcastle manager John Carver said his captain could have been blinded after the coin missed the Argentine defender's eye by "an inch".
There were also reports of a coin being thrown at Adam Lallana as he celebrated putting Liverpool in front in their FA Cup 2-1 victory on Saturday.
Palace have appealed for help in tracking down the offenders and warned they will not be welcome at Selhurst Park once they have been caught.
A club statement said: "We have conducted our own investigation into the incidents at our last two home matches, as well as making our CCTV footage available to the police.
"We take a zero tolerance approach to this sort of behaviour and, if the perpetrators are identified, they will be banned indefinitely from the stadium. If they are season ticket holders their cards will be made void without a refund.
"The stupid behaviour of a few supporters risks creating a negative image of our club and we would appreciate the help of Palace fans in identifying the culprits, who are not welcome at Selhurst Park.
"The club already has extensive security measures in place, including body cameras for stewards, and will continue to improve CCTV coverage at the ground."
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