The 19-year-old, who was formerly at Stars of Africa, scored his first PSL goal in style in the 1-0 win over Orlando Pirates on Sunday.
Sam pounced on a defensive lapse by Pirates with an overhead kick 17 minutes in at Free State Stadium.
"He [Sam] is 19 years old. If he is good enough he is old enough," said Komphela.
"We just have to guide him and give him support. We all have our own weaknesses and strengths. He has his strength where he has weakness. We give him support and depend on the senior players. But everything has been going well for him."
Meanwhile, Komphela is naturally delighted Phunya Sele Sele have won their first three games of the season. The form is surprising given that some players are owed money by the club, which is set to change hands - pending PSL approval.
"We are delighted with the results," said the former Kaizer Chiefs mentor.
"What is important in the PSL are these three points. It gives confidence and belief in the team, and there is gonna be faith.
"That's all we enjoy, three points, three out of three, clean sheets. They are having fun and we are moving on."
Siwelele are set to travel to Johannesburg to face Chiefs in their next league match at FNB Stadium on August 29.