Exeter make one change to the starting line up for their Heineken Champions Cup quarter-final with Stormers, while Stuart Hogg returns to the bench.
Olly Woodburn is named in the Exeter XV after having to withdraw from the side before the last 16 win over Montpellier.
Hogg has recovered from an ankle injury to be named on the bench, where he replaces Josh Hodge.
Centre Ruhan Nel will make his 50th club appearance for the visitors.
The South African side make two changes in the pack, with Junior Pokomela replacing Deon Fourie at flanker and Marcel Theunissen starting at number eight instead of Hacjivah Dayimani.
The winners will face either holders La Rochelle or three-time winners Saracens in the semi-finals.
'Baseline'
Exeter director of rugby Rob Baxter says his side's extra-time win over Montpellier, clinched courtesy of the hosts scoring more tries, must be the "baseline" of their level of performance.
"I said to the lads in the first meeting this week, I'm only going to keep saying the same things to you," said Baxter. "I am not going to try and change what I'm asking from you each week.
"I expect you to work hard, commit to one another, sacrifice a bit for one another and make ourselves hard to beat.
"We need to be comfortable with last week's performance being a baseline because performances like last week have been the foundation for a lot of our success over the years.
"Yes, we could easily have lost had we knocked the ball on or whatever, but if you get that baseline you start to win games."
'Full tilt'
Stormers are one of three South African sides still in the competition after their making their Champions Cup debut this season.
Head coach John Dobson says his side will have to be at their best to beat the 2020 winners.
"This is a huge knock-out match, so we have to give it a full tilt," said Dobson.
"Exeter have a great record at home, so we know it will take a full effort from all 23 to get the result we need on Saturday.
"Ruhan [Nel] always puts the team first and sets a great example for those around him in the way he approaches the game. We are lucky to have him and hopefully the team can make his 50th a memorable one."
Teams
Exeter: Wyatt; Nowell (c), Slade, O'Brien, Woodburn; J Simmonds, Becconsall; Sio, Frost, Street, Gray, Jenkins, Kirsten, Tshiunza, S Simmonds.
Replacements: Yeandle, Abuladze, Iosefa-Scott, Davis, Ewers, Cairns, Skinner, Hogg
Stormers: Willemse; Hartzenberg, Nel, Du Plessis, Seabelo; Libbok, Jantjies; Kitshoff (c), Dweba, Malherbe, Van Rhyn, Orie, Pokomela, Dixon, Theunissen.
Replacements: Kotze, Vermaak, Fouche, Porter, Engelbrecht, Dayimani, De Wet, Blommetjies.