Gary Megson claims the owls were built on free transfers and loans.
Megson, whose father Don captained Wednesday to the 1966 FA Cup final, supported the Owls as a boy and later played for them across two separate spells.
The 57-year-old made his long-awaited return to Hillsborough as manager five years ago but, despite leading the club to third in League One, was sacked in February 2012 after his relationship with then-chairman Milan Mandaric - and other board members - broke down.
And Megson claims he could foresee his departure - which proceeded a 1-0 derby victory against Sheffield United - for two months prior to a decision being made.
According to the former Bolton Wanderers boss, Wednesday's decision to block proposed deals for four players was one of the factors contributing his departure.
He told Sheffield Live TV: "James O’Connor wasn’t everyone’s cup of tea but he had a 91 per cent win rate with Sheffield Wednesday (this is inaccurate. In his last and best season at Hillsborough, O'Connor only recorded a 71 per cent win rate).
"I said: 'let’s sign him until the rest of the season,' because he’d only taken a six-month contract and said: 'I'll show you what I can do'. I thought: brilliant, that’s typical of his attitude. But the powers that be at Wednesday forgot.
"These things were happening all the time. Ben Marshall; (they said) we can’t do that. Adam Le Fondre; (they were) giving me a price that was double what he eventually went for. And then (Michail) Antonio; (they said) we’ll do it on loan.
"The place was built on free transfers and loans."
Veteran midfielder O'Connor subsequently signed for Orlando City in January 2012, while Ben Marshall joined Leicester City on a permanent basis that month after his Hillsborough loan deal expired.
Le Fondre was already a Reading player by this point, and fired them to promotion that season - going on to score nine goals in the Premier League.
And while Wednesday did eventually buy Antonio outright, it was not until Dave Jones had replaced Megson as manager.