Stuart Broad, Jofra Archer and Jack Leach all made a brief return to the nets after Ollie Pope smashed 132 on day two of England's final warm-up match against South Africa A.
The three bowlers have been floored by a flu-like illness over the past week and their inability to take the field
has thrown preparations for the Boxing Day Test against South Africa in Centurion up in the air.
They have been quarantined from the rest of the group to minimise risk but arrived in Benoni midway through Saturday's play, while their team-mates were fielding.
Pace bowlers Archer and Broad looked distinctly under the weather as they arrived at Willowmoore Park but managed an initial 10-minutes of bowling in draining temperatures in the practice facilities. Both men later returned to bat, while left-arm spinner Leach took part in a slightly extended bowling session.
They remain eligible to play some part in the final day of the game, when they could get some important time in the middle, but England have been cautious so far and will only allow them to feature if they are deemed both ready and non-contagious.
Saturday's morning session belonged to Pope, who converted his overnight score of 70 into a first hundred in England whites by adding 62 runs in 58 deliveries. It was an accomplished knock, comprising 22 boundaries and two sixes, and gave several glimpses of the sweet ball-striking skills which have marked the 21-year-old out as the most promising county batsman of his generation.
He was dropped once, at slip on 76, but that was par for the course as South Africa A took their tally of missed chances in the innings to seven.
Jos Buttler (32) was grassed at midwicket and a loopy top-edge from Jonny Bairstow (38 not out) went inexplicably unclaimed by either wicketkeeper or slip.
Joe Root declared as soon as Pope fell, holing out looking to clear the ropes, with a handsome score of 456 for seven.
That turned attention on the bowling attack, who had the chance to show their absent colleagues were not too badly missed. James Anderson landed the first blow in his fifth over, snagging Reeza Hendricks' outside edge with Ben Stokes holding on.
Stokes grabbed England's second wicket, bowling Pieter Malan for 34, but Chris Woakes and Sam Curran turned in quiet spells as the hosts reached 107 for two at tea.
Leg-spinner Matt Parkinson had a difficult time against an Invitational XI earlier in the week, when he went at 5.6 an over, but was much tighter this time.
