Quinn has gone on the offensive by pointing out that Sunderland would not have been able to sign the likes of Djibril Cisse, Anton Ferdinand, Steed Malbranque, Teemu Tainio and George McCartney without Short's financial support.
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It is also clear that Short enabled Quinn to rebuff Tottenham's attempts to sign Kenwyne Jones last month by offering the Trinidad & Tobago striker a money-spinning four-and-a-half year contract.
"He doesn't tell us what to do, he supports," Quinn said. "But he likes to see us being intelligent and slick about our business, and the disposal of some excess players was a help to us economically and also to the dressing room.
"The club has never had the sort of backing before that he is providing now, and we will have it as long as we are showing ourselves to be a smart outfit.
"Quinn continued: "Ellis Short's money was responsible for the three Spurs players, Ferdinand and McCartney coming to the club, as well as Djibril's loan fee. We were able to bring all of them in because of Ellis Short.
"The original Drumaville investors had the option of being bought out, of taking Ellis's money, but they said no.
"They wanted to dilute the shares so that his money could be used on players, so his money was vital.
"Sunderland fans won't understand how much because he doesn't like publicity.
"And he has options to take more of a stake than he currently has over a period of time, and that will again go on investment in players."
Keane broke his silence on his decision to resign in an interview with the Irish Times last weekend and pointed the finger of blame at Short.
"We had sat down with him a couple of times, Niall and I," the former Manchester United skipper said.
"I went down to London to meet him twice. I thought, hmm, the dynamics are changing here. He said he had read my book. I felt he was thinking from the start that I wasn't for him. He sort of knew this wasn't going to be a long-term relationship."