But when the message came, it had no ill feelings. Mugabe called Mandela the great icon of African liberation, freedom fighter, a beacon of excellence and a humble and compassionate leader.
Mandela's death on Thursday night has stirred debate in Zimbabwe as people draw comparisons of him with Mugabe, who had a rather frosty relationship with the late world icon.
Mandela was 95 and Mugabe is 90, and both spent long periods in jail in their quest for independence – Mugabe spent more than 10 years held by the Ian Smith regime against Mandela's 27.
They clashed publicly in 1998 when Mandela was still president over how to deal with the Laurent Kabila-led Democratic Republic of Congo (DRC) following a rebel offensive in that country. Mandela as chairperson of the Southern African Development Community opposed bailing out Kabila through war, favouring a diplomatic solution, but Mugabe wanted military intervention. Zimbabwe sent its forces to back Kabila.
Mandela's most scathing attack on Mugabe came in June 2008 when he spoke at a dinner in London to mark his 90th birthday. At the time Zimbabwe was preparing for a presidential election run-off between Mugabe and MDC-T leader Morgan Tsvangirai. Mugabe had lost the first round of elections and a violent campaign was under way.
Mandela said: "We watch with sadness the continuing tragedy in Darfur. Nearer to home we have seen the outbreak of violence against fellow Africans in our own country and the tragic failure of leadership in our neighbouring Zimbabwe."
Mugabe, too, made no secret of what he thought of Mandela, telling Dali Tambo in a People of the South interview on the South African Broadcasting Corporation in June this year that Mandela had gone out of his way to please white South Africans.
"They [whites] will praise you only if you are doing things that please them. Mandela has gone a bit too far in doing good to the non-black communities, really in some cases at the expense of [blacks]," Mugabe said. "That is being too saintly, too good, too much of a saint."
'He did not do enough for his people'
Zanu-PF officials who spoke to the Mail & Guardian of condition of anonymity said Mugabe's belief is widely shared by party officials, who feel Mandela had done very little to address the imbalance caused by colonialism and to economically empower the black people.
"Naturally we will speak good of him [Mandela] but everyone knows he did not do enough for his people," said a senior Zanu-PF official, who is also a minister.
Zimbabwe's social media has been abuzz with tributes to Mandela and debate comparing the two leaders. Strong comparisons were drawn to Mandela, who served a single presidential term against Mugabe, who is serving his seventh term.
'I wish you had done more'
State media largely ignored Mandela's death. On Zimbabwe's only television channel – the state-controlled Zimbabwe Broadcasting Corporation – Mandela's death was reported but it was not given much prominence. The station chose to focus on the late Brigadier General Misheck Tanyanyiwa, who has been declared a national hero.
Editor of the state-controlled daily Herald, Caesar Zwayi caused a storm on Facebook when he posted "R.I.P (Rest In Peace) Nelson Mandela, you played your part for South Africa though I wish you had done more."
Some supported Zwayi's view, and declared Mandela was not a hero.
"Personally he is not my hero. It is the international media that makes him a hero because he walk[s] their talk and left the means of production and South Africa in the hands of whites … President Mugabe's reputation has been tarnished by the international media because he doesn't walk their talk unlike Mandela. He should have done more for poor Africans," wrote Admire Tarasana.
Mungate Godwin was more brutal: "The problems South Africa is facing today are originating from the time when he was the president. He is a famous prisoner who sacrificed the dream of his people on the alter of expedience."
Others where angered by the remarks and said Africa would have been a better place if more leaders followed Mandela's example.
"Nelson Mandela RIP you were a true Hero, you never killed, tortured or massacred; you never reduced your own people to destitutes [sic]; you never destroyed your economy for your own benefit and lie to people that you are indigenising; you never hung to power even though you were dearly loved by your own people," wrote Jairos Chimhungwe in response to Zwayi.
Masola Wa Dabudabu, a socio-political commentator and former Daily News columnist, posted pictures of Mandela and Mugabe before writing: "Munhu akanaka haararame. Kunosara mhondi nevaroyi", a Shona saying which means evil people normally outlive good persons.