Kagiso Rabada, at 22, has become the leader of the pace attack following an injury to Morne Morkel during South Africa's 333-run win in the first Test in Potchefstroom.
Morne's absence added to injuries which have kept Dale Steyn, Vernon Philander and Chris Morris out of action.
In the absence of Morkel, Du Plessis hinted strongly that South Africa might pack their pace bowling attack, possibly bringing in uncapped Dane Paterson as well as left-handed all-rounder Wayne Parnell in order to have four front-line seam bowlers.
The South African captain said he expected pitch conditions to give more encouragement to bowlers than in Potchefstroom.
"There's not as much grass as there was a couple of days ago and it's thin grass, but it hasn't been rolled as flat as Potch. Just playing in the nets and out there in the middle there was a little more pace and bounce."
Looking to the future of South Africa's attack, Du Plessis, 33, said age was a factor, with Steyn, Philander and Morkel all on the wrong side of 30.
He said the bowlers would have to work "a little harder" in order to extend their careers, admitting: "I need a 40-minute stretch before I can do anything."
In the meantime, there were opportunities for the fast bowlers in action in Bloemfontein to stake their claim for future selection.
"With big players missing, it is really important to see what our resources are," said Du Plessis, who added that he was looking for "another dominating performance" to complete the two-match series.
Bangladesh captain Mushfiqur Rahim did not hold a formal press conference but told Bangladesh journalists that Soumya Sarkar, who missed the first Test because of a shoulder injury, was fit. He is the likely replacement for experienced opening batsman Tamim Iqbal.
Rahim said there was a possibility that there might be one or more changes to Bangladesh's seam bowling line-up.
"This is more of a South African wicket," said Rahim.
"It was more like our type of wicket in the previous game but we couldn't execute well. But it doesn't necessarily mean we can't play well in tough conditions. We lost badly in the first Test because we made silly mistakes."
chris harrisdale steynFaf du Plessiskagiso rabadamorne morkelSouth Africa vs BangladeshSouth Africa vs Bangladesh 2017Vernon Philander
First Published: October 5, 2017, 6:13 PM IST