Botham, who is embarking on charity walk in aid of Leukaemia Research, says talk of another 5-0 defeat is simply bravado and expects Kevin Pietersen and his side to win back the famous urn.
"Warney's just sore because he didn't make the cut at the Dunhill Links last week!", he told Sky Sports News.
"I wouldn't expect anything else from Warney, but I honestly believe if this England side stays together and they stay fit, they'll beat Australia - and I think Australia know it.
"They'll start talking themselves up - but hopefully to no avail."
Botham also blasted Sri Lanka for threatening to send a weakened side over to England next summer.
The tourists had hinted that due to IPL commitments they will not be sending a star-studded side for what is the final warm-up before the Aussies hit these shores.
"If you ask me, it's a total waste of time," he said.
"England have got the Ashes coming up and I do think it's an insult to the English public for them to send a weakened side and I think it's something the authorities should look at.
"It was not so long ago that England said they would send a weakened side to the ICC Champions Trophy and they were threatened with a big fine.
"I think the authorities need to sit down and look the schedule. Maybe they need to lose a tournament - maybe the ICC which is scheduled for Pakistan November, because there's got to be major security worries there.
"To lose the odd tournament may not be such a bad thing because you can gill the goose that lays the golden egg.
"You can saturate the market and with the Ashes coming up I don't think England need to clutter up their itinerary - especially if Sri Lanka send a weakened side."