However, Jimmy Floyd Hasselbaink - who has been sidelined for the last three games with suspension - played in a specially arranged practice match on Tuesday.
And Wales Under-21 defender Darcy Blake is back in contention having come through an extensive training session on Wednesday.
Blake looked to be ruled out of the Wembley tie when he was injured against Bristol City a week last Saturday.
"I've always maintained that someone's loss is always someone else's gain and football is littered with that," Jones added.
"If it (injuries) are there I've learnt not to worry because you can't do anything about it
"Thommo and Paul felt their hamstrings so hopefully it was just a little bit of tiredness after Saturday's game because that was another tough one for us, so we'll see.
"If I was playing in a semi-final of the FA Cup I would play with a broken leg. It would take more than that to keep me out, so I would be disappointed if they weren't ready."
Tuesday's scoreless match at Ninian Park against their fellow FA Cup semi-finalists from the Midlands did neither side any favours in their search for promotion from the Championship.
The Bluebirds' prospects of booking a play-off place now look increasingly difficult as they remain in 12th place and five points adrift of sixth-placed Wolves.
While West Brom, who they could meet at Wembley later in May if the Baggies beat Portsmouth in their own semi-final on Saturday, are in fourth place and are two points off second place and automatic promotion to the Premier League.
Staffordshire referee Alan Wiley will be in charge of the Cardiff-Barnsley semi-final.
Wiley was in charge of Manchester United's fifth-round victory over Arsenal.
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