Newcastle United sporting director Dan Ashworth admits the club must be open to selling players in order to comply with spending restrictions.
But ex-Football Association technical director Ashworth - who began his Newcastle role in May - says such an outlay on signings is "unsustainable".
"You can't keep doing that every year," said Ashworth.
"You just can't, so consequently we have to look at some emerging talent, enhancing our academy and getting the players through from a different route."
Ashworth oversaw a busy summer in the transfer market with the Magpies breaking their transfer record to sign striker Alexander Isak in addition to recruiting Sven Botman, Matt Targett and Nick Pope.