And the former Argentine World Cup and Spurs star, giving evidence at the trial of Lou Macari, one-time Scottish striker, admitted offering his players similar illegal, under-the-counter payments while manager.
Mr Ardiles told Winchester Crown Court that he took pounds 300 as his share as manager in a pounds 5,000 tax-free bonus after Swindon beat Bolton in 1989. Mr Ardiles shared the rest among players, coaches and support staff.
He said: 'I didn't like what was going on. But it was an offer made before I arrived. I tried to make changes but I was just told to pay this money out.'
Mr Macari, former manager of Swindon, the club's ex-chairman Brian Hillier, 49, and former accountant Vivian Farrar, 41, plead not guilty to cheating the Inland Revenue by making tax-free payments to players.
Mr Ardiles, who is now manager at West Bromwich Albion, said: 'I put a lot of questions to the club. I said, 'Where is this money coming from?' I said, 'Is tax going to be paid or not?'
'I was told not to worry. I was told it either came from someone's pocket, from a supporter, anyone. But I believed money could have come from Mr Hillier's own pocket.'
Mr Ardiles said he was promised no new 'side payments' would be made while he was manager.
But before an important match against Southampton, he was forced to make his players an offer of a cash bonus if they won.
Mr Ardiles said: 'I thought long and hard about what I should do, and now I look back and think it wasn't the right thing.'
The trial was adjourned until today.Reuse content