Nxumalo, who has scored twice this season, last played for the team in a 1-0 defeat at Platinum Stars on November 1.
He was an unused substitute in a 2-2 draw with AmaZulu in the following game, but has played no part in subsequent matches against SuperSport United, Bidvest Wits, Chippa United and Kaizer Chiefs.
"If you ask me honestly, I don't know," Menzo said when asked about Nxumalo following the 1-0 loss to Chiefs at Moses Mabhida Stadium in Durban on Saturday night.
"Prince is home and then he stays away for days, or two days. For me I can't work with a player like that.
"So I don't know where he is. I'll see him when he's back, when he thinks he wants to come back... that's all."
Nxumalo netted six times in 26 outings last term, having scored 13 goals in 23 showings in 2015/16 despite being troubled by epileptic attacks.