Provincial chairman Paul Mashatile was speaking at the ANCYL's 68th birthday rally at the Thembelihle informal settlement, south of Johannesburg.
He said the league needed to remain disciplined in order to successfully carry out its objectives.
"The fact that we want to renew the organisation does not mean that we must insult our leaders.
"We must have discipline.
"Discipline will help us a lot when we get to Mangaung," Mashatile said.
Mashatile once again called for a renewed party leadership.
Yesterday's proceedings resembled somewhat of a coming-out party as the youth league and the provincial ANC abandoned backroom lobbying in their push for Deputy President Kgalema Motlanthe to unseat Zuma in Mangaung in December.
Senior leaders from both organisations openly pledged support for Motlanthe, even though the deadline for the opening of nominations is almost a month away.
On stage, the youth league's leaders, led by Greater Johannesburg regional secretary Percy Ntsobi and recently reinstated provincial secretary Ayanda Kasa-Ntsobi, sang songs in praise of Motlanthe.
However, some leaders - like Young Communist League (YCL) secretary Buti Manamela and provincial youth league deputy chairman Simon Molefe - seemed uncomfortable with the pro-Motlanthe songs.
They avoided Motlanthe's name as their counterparts sang Ha'yo mathata, Kgalema ha le teng (there are no worries when Kgalema is here)."
The league's deputy president Ronald Lamola used his address to lament the ages of ANC leaders, citing international examples as the way to go.
He said leaders like US president Barack Obama ascended to the United States presidency while in his 40s, while South African leaders seemed to continually buck the trend.
Lamola also urged the league not to be shy about its preference for Motlanthe.
"We say, without fear, to comrade Kgalema that the youth wants you," he said.