Rapport, an Afrikaans newspaper said several of de Villiers' current and former team-mates revealed to them "events in recent years have led him to seriously reconsider his Test future," but Morkel indicated that was not the case.
"I think it is a story. He is still very keen to play for South Africa and to break records," Morkel said.
He did not go into any further detail about the newspaper's claims which cited the selection controversy at the 2015 World Cup - in which Vernon Philander was inserted into the semi-final XI, ahead of in-form Kyle Abbott, despite carrying a hamstring injury for most of the tournament - as one of the incidents which has contributed to what the publication called de Villiers' "unhappiness," with the current South African set-up.
The extent to which the selection for that game was influenced by a conversation between de Villiers, the coach, Russell Domingo, and Haroon Lorgat, the chief executive of CSA only became clear in the weeks following the tournament. However, sources close to the team revealed de Villiers was reluctant to play in the match because of what was perceived as interference.
A similar incident took place in the three months before Graeme Smith retired in March 2014, when CSA denied that the then-captain was considering quitting over transformation pressures.
In the time since Smith's retirement, CSA's transformation has been enhanced by greater guidelines at franchise level - which now require at least six players of colour in each team, of which three must be black African - and has extended to the national team as well. Since the World Cup semi-final, South Africa have fielded at least one black African in their team in every match in every format.
Factor in de Villiers' workload - he is now keeping wicket as well as batting a place higher in the Test team - and it's easy to see why the pressures of international cricket may be becoming too much for him. But that did not show on the second day in Kingsmead, when his 49 held together a line-up once again troubled by a misfiring top order.
Morkel explained how de Villiers' role was not limited to what he did on the field and that his behind-the-scenes contributions remain crucial to the South African changeroom. "AB is the ultimate sportsmen. He is the rock of our batting line-up," Morkel said. "Even though there was a lot of pressure on him, he has seen this movie before and he knows how to play it. The talks he gives in the dressing room give us a lot of hope. It's very inspiring and every dressing room would love to have him."
Rapport also claimed Dale Steyn, who made his debut alongside de Villiers at Port Elizabeth during the England tour in 2004-05 but who has been plagued by eight injuries in the last two-and-a-half years, is considering hanging up his boots, as is Philander, who is currently sitting out the first two Tests against England as he recovers from ankle ligament tears. However, Morkel was not asked about the fates of either of his pace-bowling partners.