Pickard, who previously guided Stefan Edberg to two Wimbledon triumphs, said his move followed differences with Rusedski over his treatment for a partially torn left ankle ligament sustained two weeks ago, compounded by the British No 1's decision to risk competing at Wimbledon.
Pickard said he made his decision to part company with Rusedski "when he stopped listening". He said: "I thought long and hard about it over the last two weeks, and after he'd been to the referee I told him our relationship was over.
"We've had trust, but over the last maybe 10 or 12 days it seemed to go out of the window... he stopped listening.
Rusedski, the No 4 seed at Wimbledon, said: "I don't think that's the most supportive way to be supportive to a person. Because I get this injury, and it happens to be Wimbledon time, and I decide to give it a go, does not give a person a reason to make that choice, but I guess it shows a person's true colours."
It is the second time in less than a year that Rusedski has split from his coach. In September, just before the US Open final, he sacked Brian Teacher.
Meanwhile, Tim Henman, Britain's other seed, was far from convincing as he went into the third round, beating David Nainkin, a South African qualifier, ranked No 234 in the world.
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