Gary Neville has accused Motherwell manager Stephen Robinson of lacking "etiquette" by discussing Salford City's spending power.
Robinson said the English fifth-tier club "blew us away with money" when the teams competed to sign a player.
The comment followed Salford's signing of striker Adam Rooney from Aberdeen.
Salford co-owner Neville tweeted: "There used to be an etiquette in football where you wouldn't talk about another club's business."
It is the second time in two days that the former Manchester United and England defender has become involved in a social media row over Salford City's affairs.
On Thursday, Accrington Stanley owner Andy Holt accused Neville, one of several ex-United players who own Salford, of trying to "steal" a place in the English Football League.
Striker Rooney, 30, is reported to be receiving a £4,000-a-week salary at Moor Lane after deciding to leave Aberdeen.
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Robinson says it is getting tougher for Scottish clubs to compete with the financial muscle of their English counterparts.
"Fifty per cent of National League clubs probably pay more than the bottom half of the Premiership," he said.
"I tried to sign a National League player and he's gone to League Two on double the money of my highest-paid player.
"I actually competed with Salford for a couple of players. I got one - Liam Donnelly - and lost out completely on the other. They blew us away with money.
"But it's not like suddenly we don't have any money. We probably have a bit more than before, so we're OK."
Despite those difficulties, Robinson says he is content with his squad strength.
As well as signing defender Donnelly from Hartlepool United, Robinson has recruited Alex Rodriguez Gorrin, Aaron Taylor-Sinclair, Mark Gillespie and Danny Johnson.
Striker Conor Sammon was also brought in this week on a season-long loan from Hearts and Robinson says his transfer business is done unless players are sold.
The Fir Park club have rejected offers for defender Cedric Kipre from Hull City and forward Ryan Bowman from Grimsby Town.
"We are a club that sells players but they won't be leaving for the money that's been offered," Robinson said.
"You have to be fair to the player and not ask for a ridiculous amount. Give us the market value and they can leave."