Marco Silva says Everton were restricting in the transfer market because of the demands of other clubs.
The Toffees tried to sign Wilfried Zaha but Crystal Palace rejected their £52m bid.
"We have some names but the market is really difficult," Silva said, when asked about trying to find a left-footed right winger.
"We had our targets for the summer and at the end of the market if you achieve 20% of those players it will be very good because the market is always changing.
"I can tell you, last season was fantastic for us. This season we have signed very good players but the market was more difficult.
"You look at the money some clubs are asking for players and the market is really difficult in England and to buy players inside is something unbelievable."