The Americans are reportedly preparing to table on offer for the striker as soon as he recovers from injury.
Mphela – who recently underwent knee surgery – has not taken part in Sundowns' pre-season training.
According to sources at the club, Houston Dynamo are likely to make a bid for Mphela during the January transfer window.
"He [Mphela] is high on their shopping list. The question is whether or not the two clubs will reach an agreement," says the source.
Sundowns spokesperson Kabelo Mosito was not forthright when asked about the possibility of Mphela moving to another club.
"I really cannot comment. I will have to get back to you on that one," Mosito says.
Mphela's agent Glyn Binkin tells KickOff.com: "There have not been any concrete offers from them [Houston Dynamo] so there is nothing to comment about.
"At the moment we are focusing on Katlego's return to full fitness."
This is not the first time that Mphela has been linked with a move to a club outside the country.
While he has – in the past – been linked to Belgian, Russian and English clubs, Sundowns have turned down a number of offers for the experienced striker.
However, with the club having signed several strikers, Downs owner Patrice Motsepe might now be more willing to let go of Mphela.