A number of tickets have appeared on the site with prices reaching £160 for a pair of junior tickets which have prompted action by the club.
A statement issued by City's ticket office says: "FOLLOWING the appearance of a series of tickets for Coventry City's FA Cup quarter-final clash with Chelsea being put up for auction on website Ebay, the club would like to stress fans both selling and purchasing these tickets run the risk of not gaining admittance to the ground on matchday"
The selling of football match tickets for profit is illegal and, as such, the football club would like to inform fans both buying and selling these tickets that it may affect their ability to both gain entry to the Ricoh Arena for Saturday's cup clash and also any fixtures in the future.
Coventry City Football Club will be monitoring the situation and, in conjunction with Ebay, will be removing the sale of Saturday's matchday tickets from the auctioning site where found."
Anyone who tries to get into home areas wearing Chelsea colours also faces the threat of not being admitted on safety grounds.
The few remaining tickets which were not taken up by season ticket holders were sold this morning and the match is now a complete sell out.