Bringing back Kevin Pietersen could "tear apart the fabric" of the England team, according to Australia's most successful coach John Buchanan.
Pietersen, sacked in February 2014, has joined Surrey in a bid to win back his England place after encouragement from new English cricket boss Colin Graves.
But Buchanan thinks the batsman's return could be "destructive".
"A decision was made for good reasons," he told BBC World Service. "Leadership is about sticking by that decision."
Buchanan also likened Pietersen - who is targeting a place in England's team to face Australia this summer - to a "child" who is determined to get his own way.
Pietersen was told his England career was over last year when England & Wales Cricket Board (ECB) managing director Paul Downton accused him of becoming "disengaged" from the team.
But incoming chairman Graves said the selectors "could not ignore" Pietersen if he scored runs in county cricket, prompting the player to cut down his Indian Premier League commitments and rejoin Surrey for the start of the season in April.
|Pietersen's Test record|
Buchanan, who won three Ashes and two World Cups as Australia coach from 1999 to 2007, believes the mixed messages from the ECB could have a detrimental effect on the England team.
"Various things have torn at the fabric of the England team and that has certainly been one of them," said Buchanan, who handled challenging players such as Shane Warne and Andrew Symonds during his coaching career.
"There has been a clear decision made by the ECB about where Pietersen fits in the English camp. Let them stick by the decision, draw that line in the sand and say this is what we really stand for.
"You will always have people like Pietersen that are game changers and they are usually difficult to handle because they are quite selfish.
"When things are going well for them, there are no better people in the team, they are caring, sharing and give a lot of support to everyone, but when things are not going well they become quite destructive. They can tear things apart."
England's national selector James Whitaker insisted last week that Pietersen was "no longer" part of his plans.
But Pietersen has spoken to Graves on the telephone and now wants face-to-face talks as he steps up his quest for a recall.
"It's like when you are a parent with a child," added Buchanan, who has written books and given lectures on leadership. "The child doesn't get his way from mum so then he goes to dad and asks dad.
"And if he still doesn't get the answer then he plays both of them off against each other. If he doesn't get his own way he certainly causes a bit of mayhem in the meantime."
Buchanan, who predicted in 2010 that Pietersen could be "a major problem" for the England team, also gave his backing to England coach Peter Moores following their dismal World Cup performance.
He said Moores should stay on for the Ashes regardless of what happens in the upcoming tour of West Indies or home series against New Zealand in May.
"He needs to be judged not just on results because there will be a number of things he is doing behind the scenes that the public don't see," added Buchanan.
"He needs to be given time and support. Then let's sit back and watch that unfold and then see how he and the team perform."