The 45-year-old, who wore a grumpy face even before sitting down for the Free State stadium conference, wrapped up proceedings with an abrupt evaluation of the press before him.
"I would like to thank the Slovak journalists who are a lot better than the foreign ones," he said, ripping off his headphones after being asked if he respected Paraguay.
Slovakia have eluded international press ever since letting slip a win in Tuesday's 1-1 draw against New Zealand with Weiss apparently wanting his squad to concentrate on being a team.
Renowned for a mood swing or two, he said his side had put that result behind them and were ready to face an "organised and hard working" Paraguay team buoyed by a 1-1 opening draw with world champions Italy.
'QUITE SAD'
"Everybody is ready, we are all looking forward to the match. It will tell a lot about the group situation," said Weiss, whose side sit in a group all level on one point.
"The atmosphere after the first match wasn't very good, it was quite sad I must say, because a goal in the very last second is a small sporting tragedy. But we have dealt with it over the past few days and now we are ready for Paraguay," he added.
Slovakia, who have no injury doubts, are expected to bring attacking midfielder Miroslav Stoch into their side with Stanislav Sestak moving up front alongside Robert Vittek.
Paraguay are well placed for a last 16 spot and a win on Sunday will take the pressure off ahead of their June 24 match with New Zealand.
Defeat for Slovakia, who have yet to face Italy, would leave their first World Cup campaign hanging by a thread.
"Paraguay will force us to be more disciplined and more speedy ... they have very good strikers and they have a strong defence, so there is not really a weak point in their team," Weiss said.
Weiss's son, Vladimir junior, a midfielder in the Slovakia squad clearly did not share his father's demeanour.
"I don't know there's any pressure. We came here to enjoy ourselves and with a little bit of luck we can do it," he told reporters.
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