The Auckland members of the Kiwis train-on squad start training today, but Mannering won't be among them.
"I told him to take his time and Simon wouldn't take long to get his fitness back anyway," said Kearney. "He's such a competitor, and whenever he is right to come back to the group we will deal with it then."
Kearney also remains optimistic about vice-captain Kieran Foran, who was hampered by back and hamstring issues throughout the NRL season.
"He's in Fiji and enjoying that and we will have a good chat when he gets back."
Meanwhile, five more names were added to the Kiwis squad yesterday, including uncapped Bulldogs winger Curtis Rona and young Tigers five eighth Te Maire Martin.
Rona has been a revelation this season, scoring 23 tries in 25 games on the end of the Canterbury backline
"He had a pretty exceptional year and I have been very impressed with how he has gone," said Kearney.
The 23-year-old was also eligible to play for Australia - and talked earlier this year of a long held dream to turn out for Queensland - but Kearney said he has never discussed allegiances with Rona.
"I didn't ask him who he was aligned to," said Kearney. "I always assumed he was a New Zealander and he wanted to play for the Kiwis."
At least one wing spot is open in the touring party, as Manu Vatuvei and Dallin Watene-Zelezniak are unavailable for the trip.
The 19-year-old Martin, who has been named in the Holden Cup team of the year over the last two seasons, is an exciting prospect.
He looks an outside chance to be on the plane, though with the Kiwis lack of depth in the halves he can't be discounted.
