The 20-year-old becomes the latest former youth international to graduate into the senior team, following in the footsteps of Karabo Meso, Miané Smit, Seshnie Naidu and Ayanda Hlubi.
Coach Mandla Mashimbyi explained what led to Reyneke being picked for the three-match series, saying she brings a fresh dynamic into the team.
"Kayla is an off spinner of which we've been struggling to get off late. We don't have an off spinner that's playing for our team, we've got bowlers that take the ball away from the bat and not into the batter and also she's a good batsman and in terms of T20 cricket she's very explosive,” Mashimbyi said.
“So, we felt that that's probably the right mix we're looking for from a Kayla point of view. She was the U19 captain, she's got a good cricket brain on her and she's done well domestically as well.
“We just had a camp a few days ago and she showed a lot of promise as well. I like what I hear about her and I like what I saw when I had an opportunity to see what she can do."
Conversely, Smit misses out completely from both the T20 and ODI squads for the inbound series, which was a bit of a surprise given that she scored her maiden half century in the series against Ireland in December.
Mashimbyi admitted that it was not an easy decision to leave her out, but was looking at other factors contributing to the team’s balance.
"And as for Miane, it was quite unfortunate, it was a tough decision to make because I know that she's definitely someone that's gonna be a big player for the future but I'm not scared to make such decisions as well, as tough as it is,” the coach added.
“At the same time she's not out of the equation, she's still part of the squad, it's just that in terms of the team yeah it was quite a tough one to keep her in the Pakistan squad in both formats.
“We were looking at something and then we felt that the players will probably bring a lot more from a skill point of view in terms of maybe the offspin side of things. It's not because she's a bad player or anything like that, it's just unfortunate in terms of how we structured our team and the balance that we're looking for and that's why she missed out."