Meyiwa let in only one late strike in Pirates' 3-1 Premiership victory over Mamelodi Sundowns at Loftus Versfeld.
De Sa surprised many with his inclusion of the 25-year-old shot-stopper, who has spent his entire career with the Buccaneers, graduating from the Orlando Pirates youth development side in 2006 before making his senior debut for the Soweto outfit the same year.
"I have always picked players by what I see at training," De Sa said after their win.
"Senzo has been outstanding the last couple of weeks. He's worked hard.
"Moeneeb (Josephs) hasn't been at his best entirely -- he's had a few weaker moments -- and it's only fair to give the youngster a chance."
De Sa, who said he did not have a rotation policy when it came to his goalkeepers, added that Meyiwa had shown he was ready to make the step up and he would be monitoring the progress of the young number one.
"He has been great at training, so if anybody does that, it doesn't matter what position he plays, if he shows that he's knocking on the door and keeps pushing the other guy, you have to throw him in," De Sa said.
"I've worked with Senzo before, I know him pretty well and I think we needed him today.
"He comes out for crosses and that's not Moeneeb's strongest, and today it was important to have a goalkeeper who comes through people and comes for everything."
Meyiwa produced a solid display in goals, picking up an injury in the second half that required stitches, and was unfortunate to concede with two minutes of regulation time remaining.
"I think he's got about eight or nine stitches on his face now and he's a character," De Sa said.
"I think he pushed Moeneeb, and Senzo, if he's fit, will play (against Free State Stars) on Saturday.
"He's showed the mettle and he'll play. Like any other position… if you show, you play."