After the final whistle in south Wales Malky Mackay's men will be handed the trophy but Barnett, carried off the field on the shoulders of jubilant supporters following their 1-1 draw with Burnley last week, will not be there after being recalled by parent club Norwich.
Barnett had been a key part of the promotion-winning City side, playing seven times during the run-in in the absence of captain Mark Hudson and his place in the starting line-up could be taken by youngster Ben Nugent.
Meanwhile striker Nicky Maynard could feature in next weekend's clash at Hull after coming through 75 minutes in a behind-closed-doors 0-0 draw with Exeter on Wednesday, but this match comes too soon for the 26-year-old.
The former Bristol City forward has missed most of the campaign with a knee ligament injury and manager Malky Mackay is keen to only field the forward if he is ready for what would be a welcome return.
Fraizer Campbell will be assessed and Matt Connolly is still sidelined.