This will be a hard-hitting affair as both players have plenty of power and will look to dictate with their powerful groundstrokes to try and play first-strike tennis. Both also have excellent backhands.
Badosa takes a little more time to set up her shots, specifically on her forehand, so Keys will want to target that side and try to open up the court, specifically down the line.
Conversely, the Spaniard is going to aim to play steady baseline tennis to try and force errors from the American, which is something that has plagued her over the years.
The serve is a weapon for both players, with the one getting more free points likely to have the edge. Badosa also has the advantage in movement as she is very good in that department for a tall player.
This is a tremendous opportunity for both players. Their paths are nearly identical: easy wins early on before severe tests in the third round. It make a little time to feel each other out having never played before.
While Keys has been to the later stages of majors more often than Badosa, the Spaniard is likelier to be solid as she has more margin in her game and in a close match, that will be the difference.
Prediction: Paula Badosa in three sets