Bautista Agut booked his place in the third round by beating Mackenzie McDonald in three sets on Wednesday.
Later in the day, Federer then saw off the challenge of Daniil Medvedev 6-4, 4-6, 6-4, albeit with a very nervy finish.
The two are set to clash on Thursday with a place in the quarter-finals the prize for the winner. And Bautista Agut is just glad to be back playing free from injury after recently recovering from a stomach injury.
“Physically I’ve had a very bad time in recent months and little by little I’m going to find myself better,” he said.
“Now what I need is to catch the rhythm of the match, take a continuity in competition and gradually find myself better.
“After everything I’ve spent this year for me every win is a prize, I want to compete, to win games, you have to go little by little and the sensations are good.”
Federer has won all seven of his previous meetings with Bautista Agut, but the Spaniard feels he is adjusting well to the pace of the court in China.
“The tracks are fast but the balls are even more, it’s a faster surface than usual but I try to compete in all the places and adapt as well as possible,” he added
“The key [to the second-round victory] was in the second set when I had a bit more calm and patience to the exchanges.
“I got hold of the track and won almost all the points played.”
Meanwhile, Federer acknowledges that Bautista Agut is going to be another tricky opponent.
“He has done well here before beating Novak [Djokovic] so I am aware of that,” Federer said.
“I haven’t followed his season super-closely to be honest because I check in and out of the tour too often.
“I have a lot of respect for him and he is a tough guy.
“I am excited at playing Roberto. I like his demeanour, he is a great fighter and I like playing against those type of players.”