The 27-year-old continues to play his heart out as he's still contracted to the club, and this was evident when he scored two brilliant free-kicks to help Sundowns beat Platinum Stars 3-0 on Saturday evening.
Billiat's current deal with Masandawana will expire at the end of June this year.
Asked to provide an update on Billiat's future, Mosimane said the situation is now dealt at a level above him, saying it's between the player, his agent and the Sundowns board, before going further to state that they would welcome the attacker if he decides to stay.
However, it's now up to the 2016 African champions to either cash in on him before the transfer window slams shut on January 31 or risk losing him for free at the end of the current campaign.
"It's not in my hands, but what's important is for us to have a back up," Mosimane told the media on Saturday night.
"We love Khama. If he stays‚ okay, but that's between Khama and the agent as well as the board of Sundowns," revealed the 53-year-old.
"My job is to ensure that the team keeps going and stays at the top of the log. The rest‚ I'm no longer part of it," added Mosimane.
Mosimane has already brought in a possible replacement in Gaston Sirino should Sundowns eventually lose Billiat.
Billiat took his game to another level soon after joining the Tshwane giants from Ajax Cape Town in 2013.
Since 2013, he has managed to scored 43 goals in 129 official matches for the Brazilians. He's currently sitting on five goals and four assists in 10 appearances this season.
He has also won six major trophies, including two league titles, the Caf Champions League and Caf Super Cup among others.