United have already signed striker David Zulu from Black Leopards, while Orlando Pirates defender Siyabonga Zulu may stay with the Premiership returnees following a loan spell at Philippi Stadium.
According to a source close to the Chilli Boys, Mvelase's deal with the club is as good as done.
"There are a few things left before Mpho signs on the dotted line. The club is also interested to sign Zulu who was on loan to United from Pirates," says the source.