Black Cats manager Steve Bruce is believed to be a big admirer of teenage defender Clyne, while Arsenal have also been linked with the talented full-back.
Striker Victor Moses is also on the radar of a number of top-flight clubs, and the interest does not come as a surprise to Warnock.
"There will be clubs sniffing round both Clyne and Victor - we have to put up with that," Warnock told the Croydon Advertiser.
"If Sunderland aren't interested in Clyne then there's something wrong.
"Whether Premier League clubs will put them in the first team straight away is another question, but all the clubs will be looking at young English players because of the new homegrown quota rules."