Manager Ronald Koeman has insisted that Everton need to bring in a new striker before the close of the transfer window on Thursday night.
The Toffees - who have spent over £130m already this summer - have already signed Sandro Ramirez from Malaga and re-signed
"You know if you play three really tough games in five, six days and you need to travel, you can’t do it with eleven players, you need more and in that situation we were a little bit unlucky but we missed six, seven players," the Dutchman told the BBC.
“I don't know," he said when asked about Costa. "We are looking to the players who are maybe available. If we sign somebody, it's somebody to make the team better.
"I don't speak about names of players. We are looking and doing our job. Hopefully we will arrange it for next week.
“I'm always confident because we did some good business, but the board knows the importance of the two signings.”