Stockley is a young striker who scored a bagful of goals as Exeter reached the League Twoplay offs last season. He would fit the young up and coming mould that Preston like to keep to.
The striker has one year left on his contract and Exeter may look to cash in as they did with Storey who made the move to Preston earlier in pre-season.
Ipswich and MK Dons are also said to be interested in the frontman.