Yerry Mina and Andre Gomes will not make their Everton debuts for another three weeks.
Both players sealed transfer deadline day moves from Barcelona earlier this month, with Mina arriving on a permanent deal worth an initial £27.2 million.
Marco Silva had hoped to hand the defender his bow in the Blues’ to Bournemouth but is unlikely to resume training before the international break.
Gomes’ recovery from a hamstring injury picked up during Barca’s pre-season tour of the United States is also set to delayed his own return to action.
It is understood that the Portugal international, currently on a season-long loan from the Nou Camp, faces up to five weeks on the sidelines.
Should the pair’s recoveries remain unchanged, they would be available to feature in Everton’s clash with West Ham at Goodison Park on September 16.
“It looks maybe after the international break they can start working with us,” said Silva.
“He (Mina) is recovering from an old injury. It is not something that happened here and not something special.
“The report I had from our medical staff is it is not serious but you have to take more days to put him in at that level. It is an injury he arrived here with.”