The Brazilians were in Japan nearly nine years ago, losing both matches in Osaka at a tournament with only seven teams and two host cities.
Now that the world governing body has finally launched a 32-club competition with 12 venues in the USA, Onyango sees this as a significant improvement.
Sundowns face Ulsan HD in Orlando, Florida, for their Group F opener to be followed by fixtures against Borussia Dortmund and Fluminense.
The veteran keeper believes this to be a game-changer.
"What's different? I think it is the sheer number of teams, this Club World Cup has 32 teams which makes it incredible because you get to see so many quality payers on show.
"There's a better format to this competition as well, teams can now prepare for each group game, and maybe the last 16," said the Sundowns shotstopper.
Onyango adds that with more games comes the opportunity to give Africa, especially Sundowns, the chance to challenge the favourites.
"The sky is the limit. We must leave absolutely everything on the pitch, but we also intend to play beautiful football so that the people who are watching from all around the world are entertained," expressed the Ugandan goalkeeper.
There’s an expectation for Sundowns to carry the torch for the PSL, and the veteran Onyango hopes they live up to those expectations.
With crowd attendance quite satisfactory considering how spread out the teams are at the Club World Cup, the former Uganda no.1 believes that also vindicates FIFA for the expansion.
"I think this tournament has started off very well, with big crowds coming to support football. The quality of football that some of the teams have played so far, shows that this is the highest level," concluded Onyango.