Essien puts international career on hold
Essien has been missing without explanation from two Ghana squads named since the World Cup, including the selection for Sunday's start of the 2012 African Nations Cup qualifiers.
Rajevac told the BBC Essien had asked for time off to consolidate his place in the Chelsea side after a long injury lay-off.
"He contacted me and wanted to ask for permission to be excused for a while," Rajevac said in Swaziland ahead of Sunday's Group qualifier.
"I understood his thoughts and of course I wanted to help him to get into his old form, to start playing regularly and I gave that permission," the Serbian-born coach added.
Essien, who missed the World Cup in South Africa, has suffered two serious injuries while on past international duty.
"I'm sure that after sometime he will come back to the national team," Rajevac added.
Essien has won 50 caps for his country and played in the 2006 World Cup for the Black Stars.