Aiken has been their most important player for almost a decade and Fowler-Reid is arguably the most dominant shooter in the sport, having led the ANZ Championship shooting statistics for the past two seasons, but both were unavailable for the tour.
"Their defensive end is pretty similar to last year but I'm unsure about their attacking end," said Southby. "We know they are athletic and fast but we are not sure how they are going to play. The big thing for us is to embed our game plan but be aware of what they can do to us."
Southby shrugged off the idea that the weakened Jamaicans won't provide much of a challenge.
"You want to be challenged all the time but we just want to focus on ourselves, our standards and not let things drop," said Southby.
Jamaica isn't a regular opponent for the Ferns - with only five meetings since 2010 - but they can be a tricky proposition. The last three encounters have featured winning margins of eight goals or less, with the clash at the 2015 world championships particularly tight (55-48).
Southby plans to use her entire squad across this series, aware it could be their last hit out against Jamaica before the 2018 Commonwealth Games.
The Sunshine Girls have beaten the Ferns on two previous occasions (2002 and 2009), both in Kingston.
Tomorrow's international starts at 7.40pm, followed by tests in Palmerston North (Wednesday) and Rotorua (Saturday).