Palace have been asking for £80 million for Zaha, but Everton are hopeful that they can get a deal done by offering them Tosun and £60 million.
If Marcel Brands pulls off the ambitious move then it would have to be seen as his most brilliant transfer act since moving to the club.
Tosun has never shown that he is up to leading the line for Everton during his time at the club, and he is clearly a player who Marco Silva has doubts about.
If Everton can offload him to get the price for Zaha down, then it should be seen as a major transfer victory.
Everton look likely to make a sizeable loss on Tosun when they do come to sell him, as they overpaid to buy him from Besiktas.
But in Palace they may have found a potential suitor, and Zaha’s potential arrival at Goodison Park should be so exciting.
There has been a surprising amount of scepticism from some Everton supporters at the deal, as even at £60 million Zaha looks expensive.
But if the Toffees are looking to break into the European places then Zaha is exactly the player they should be going for.
The Ivorian international is arguably the best player outside the top six, and has carried Palace for the past two seasons.
Zaha scored 10 goals and claimed claimed five assists in the Premier League last season, in one of the most defensive teams in the division.
At Everton, where he would have more attacking flair around him, Zaha could do so much damage.
It is not just about what Zaha would be able to do either.
The 26-year-old is a player who naturally attracts attention, and his arrival could create even more space for the likes of Gylfi Sigurdsson and Richarlison to thrive.
The transfer still looks very ambitious at this time, but if Everton do manage to complete it, and get rid of Tosun in the process, then it could be a wonderful piece of business.
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