Riveiro addressed the media during a Carling Knockout/Carling Cup Campaign Media update in Johannesburg on Wednesday, ahead of the December 6 final between Pirates and Marumo Gallants.
With scrutiny mounting on the 20-year-old, the Spaniard stepped in to defend the attacker's long-term trajectory.
"Rele is a very mature guy and if it's true what you're saying, which I cannot say or confirm right now, I'm sure he's going to find a way to come back to the right track and still perform the way he used to do it," Riveiro told the media.
"Having ups and downs in a football career is normal. You cannot be at your peak constantly."
Mofokeng, who flourished under Riveiro during his time at the Soweto giants, has endured a disrupted campaign due to limited minutes and fitness concerns.
His omission from the latest Bafana Bafana squad intensified debate around his readiness for international football, fuelling further pressure.
Riveiro pushed back against claims that the youngster is in decline, arguing that expectations around Mofokeng are often inflated because his best performances appear effortless.
He believes the attacker's mentality and natural talent will allow him to overcome his current challenges and return stronger.
The former Pirates coach remains convinced that Mofokeng's form dip is temporary - a typical hurdle for a player still at the early stages of his professional journey.
