Roger Federer faces Filip Krajinovic in the round of 32 on Monday while Stefanos Tsitsipas goes up against Leonardo Mayer.
Federer will be hoping for a straight-sets victory over the Serbian after he suffered a wobble against Radu Albot last time out.
Tsitsipas saw off American challenger Mackenzie McDonald in the last 64, but Mayer will be hoping to cause a shock against the Australian Open semi-finalist.
Federer is currently ranked as world No 5 but he will be hoping to improve on that before the French Open begins in May.
One worry for fans of the Swiss veteran will be his emotional revelation that he forgot key instructions from his coach Ivan Ljubicic during his last match.
He said on Saturday: “I started forgetting things that my coach told me in the mix of things so it got really complicated in my head, but I was able to pull it off and played some good tennis, and I needed to.
“I was very much tested by Albot, it wasn’t easy.
“He got off to a good start and I struggled early on, with decision making and getting use to the stadium and the conditions.”
When asked about his next opponent, Krajinovic, the 37-year-old warned fans not to expect a routine victory.
“I practised with him in Australia and he played very well against be there, and I like his game,” Federer added.
“Krajinovic takes the ball early he can play down the line and he is very steady.
“I think that his talent makes him a dangerous player plus he has just beaten Stan [Wawrinka] so I’m sure he’s ready.”
Miami Open day 6 order of play
Stadium
Filip Krajinovic vs Roger Federer (5:00 pm)
Frances Tiafoe vs David Ferrer (11:30 pm)
Grandstand
Kevin Anderson vs Joao Sousa (4:00 pm)
Denis Shapovalov vs Andrey Rublev (6:30 pm)
Stefanos Tsitsipas vs Leonardo Mayer (7:00 pm)
Court 1
Grigor Dimitrov vs Jordan Thompson (3:00 pm)
Daniil Medvedev vs Reilly Opelka (5:45 pm)
Marco Cecchinato vs David Goffin (7:00 pm)