The Sky Blues had the former defender and Reading player on trial this week and had offered him a month long deal.
It is understood that De La Cruz was looking for a deal until January and with both parties wide of an agreement, any hope of a deal faded.
Ray Ranson told the CT: "We have got Isaac Osbourne coming back and Stephen Wright could be coming back in two to three weeks,so we are not prepared to bring in a specialized right back on a three or four month contract.
"It is unfortunate but that's where we are. We will just have to see how Stephen Wright progresses".