England fast bowlers Stuart Broad and Jofra Archer bowled at full pace in the nets on Monday, raising hopes that they would both be fit for the first Test against South Africa, starting at SuperSport Park on Thursday.
"They're exactly where we hoped they would be," said England coach Chris Silverwood, who said both bowlers would be considered for selection if they continued to make progress.
Broad, Archer and left-arm spinner Jack Leach have yet to bowl in a match situation on the tour after falling ill and missing both the touring team's warm-up match.
Leach also bowled in the nets but may miss out on selection if England decide to field an all-seam attack on a ground which has not been receptive to spin in recent years.
Broad and Archer both bowled five overs at full pace in an optional practice attended by the three recovering bowlers as well as Craig Overton and Dom Bess, who arrived in South Africa on Saturday to be on standby in case the originally-selected players were not fit.
Silverwood said he did not believe it would be a gamble to pick Broad and Archer, provided they came through the next two days in good health.
"If Broady tells me he's fit I'll believe him," said Silverwood.
"He's got a lot of experience, he knows his body and he knows what he needs to do during the Test match. Jofra, too. He's had two good days and as long as his pace is up and he feels good and gets the practice he needs he'll be a serious contender."
"You look at what is effective on this ground. We're not definitely going all-seam but we'll discuss it over the next few days."
"The opposition we faced was a really good side. I think both teams came away with something really positive."