The quartet have helped Orlando Pirates reach the Confederation Cup Final, with Gabuza and strike partner Erasmus netting five goals apiece in the continental competition.
Manyisa was captaining Bucs from midfield before sustaining an ankle injury, while goalkeeper Ovono has been recognised largely for starring in Equatorial Guinea's run to the Afcon semi-finals in February.
"It's an honour to be shortlisted with Shorty [Erasmus] over here. It will be great if we get all the way to the end," Gabuza is quoted as saying by Pirates on Twitter.
"We aren't looking too far ahead though. We're just keeping our feet on the ground and letting the performances do the talking.
"I'd like to thank the people who have made it possible for me to get nominated. My team, the coaches, everyone."
Erasmus added: "It's pretty cool for us players to get nominated for these awards and at such a scale because it means you're doing well."