Town are set to receive a small sell-on windfall after former striker Kieffer Moore completed his move from Barnsley to Wigan Athletic.
The fee is reported to be an initial £2.5 million rising to £3 million, lower than the figure claimed last week.
The Blues are understood to be due 10 per cent of the profit the Tykes make on Moore, 26, who Town sold to the South Yorkshiremen for £750,000 in January 2018.
That comes to £175,000, however, his former club Forest Green Rovers will be entitled to a percentage of that figure, perhaps as much as 20 per cent having picked up a six-figure sum from the big frontman's previous move.
Town have already received more significant windfalls from Adam Webster joining Brighton from Bristol City, Matt Clarke’s switch from Portsmouth to the Seagulls and Tyrone Mings’s move from AFC Bournemouth to Aston Villa.
In total, from the four deals, Town are due an initial figure probably just over £3 million.
However, with the Blues' income having been reduced by £9 million due to relegation to League One - having made an operating loss of £8.39 million in the financial year to June 2018 in line with most recent Championship seasons - manager Paul Lambert says he's not seen any of it.
"Mings, Clarke, maybe Webster, we haven’t bought one player,” the Blues boss said at Friday's press conference.
"I don’t know if the money has come in, nobody has told me it has come in. I don’t know.”
He added: "Whatever way those deals were structured before I came in, whenever the money comes in, it could be three years' time down the line, four years down the line, it could be now, I don’t know. But you haven’t seen one player I’ve bought, I’ve not bought a player.”