The 17-year-old, who currently plays for United's reserve side and the South Africa Under-19 team, could be lost to South African domestic football as the club lines up a move abroad for him.
Matthews announced that Mayo has attracted interest from two clubs in Portugal – one is believed to be Benfica while the other, as confirmed, is Sporting – the same club Bidvest Wits striker Liam Jordan has joined on a season-long loan.
"As we stand right now, there are five of our academy players that have been invited to Europe for trials," Matthews revealed at the club's awards dinner on Thursday.
"Khanyiso Mayo has been invited to Sporting Lisbon for a trial and, in principle, we have accepted that he should go.
"We also have another trial opportunity for him at another Portuguese club, should the Sporting one not work out.
Matthews added that arragements have been made for the former Amajimbos star to continue growing at the club should a move not materialise immediately, and reassures they will do everything in their efforts to secure a European move for the teenager.
"I expect that Khanyiso will have a real chance in Europe shortly, if not now," he added. "We've spoken to him and his dad [Patrick Mayo] and we have a domestic plan for him, if he needs to spend another year or two here."
"But I think it is inevitable, with the talent that he has, that he can go and play abroad and, as a club, we will do everything we can to help him achieve that goal
"Even if it is means he never kicks a ball for SuperSport, because we are grateful for what his father did for us.
"He [Patrick] was a great player for us. He came to us from Umtata Bush Bucks and went on to Kaizer Chiefs afterwards. He spent good years with us, and he was a fantastic player on the field, and now works for us as a scout."
Matthews also revealed that numerous other youngsters from the club's academy will also be attending trials in the next three month in Europe.
"There are other players from our academy that are currently in Europe, we got five other kids from our academy that are going to Europe in the next three month.
"It is a very exciting phase for us and it is not important for us if they don't make it now, they are all young and still have a chance [in future]," he concluded.