Berrettini has been forced to withdraw after being infected with corona and his place in the grand slam competition now goes to Ymer, who went out in the qualifying final against Jason Kubler.
Elias Ymer, ranked 148th in the world, now joins his brother Mikael in the tournament.
There he will face 43rd ranked Cristian Garin.
The match is played on Tuesday afternoon.
In addition to Berrettini, 17-ranked Marin Čilic has also been forced to rebid Wimbledon due to the corona.
He is replaced by the Portuguese Nuno Borges.