Khaled Nordin is the third Umno leader who has distanced the party from its former president Najib Abdul Razak in the past 24 hours.
He also backed the former minister Johari Abdul Ghani, who remarked that Najib should not have been allowed to campaign in the run-up to the Sungai Kandis by-election.
Commenting on those who criticised Johari, he said it mirrored what Umno used to be, and still is, to a certain extent.
"The feudal values are still dominant in Umno until it has hindered our progress to reform and move for the better. There is no sense of 'shame' in the feudal landscape.
"People were not held accountable because of the favours he or she gave out when he or she was in power. This narrative must go and be replaced by the real feeling of 'shame' against wrongdoings and injustice," he added in a statement.
Umno politicians, Khaled said, must be educated to understand the post-modern predicament faced by the Malays and Malaysians in general.
"But such an endeavour is long, tiring, and taxing. It will be made impossible if Umno still lives in its own labyrinth, reminiscing about the past and allows a man who is under a legal trial to be significantly involved in the party.
"Yes, we should treat him with honour and respect, but we should move on from what has passed. It is Najib who is on trial, not Umno," he added.
The former Johor menteri besar said Umno cannot commit to reform if its leaders are still in a state of denial over the injustice and corruption of the past.
"Where do we go from here? I do not have a definitive answer to that.
“But Umno shall rise from the ashes, gain the trust of everyday Malaysians, and chart a new narrative for Malay nationalism," he added.
Khaled also urged Umno members to accept the fact that the people had rejected them in the last general election.
“We are no longer the government and we no longer have the privilege to say confidently there are some Malays who are still behind our back.
"Those who deny this reality might say we still hold on to 46 percent of Malay votes. Yes, that might be true but we must also look at the demographics of these Malays and what are their values.
“We must cater to all Malays, urban, semi-urban and above all, Malaysians as a whole," he added.
Earlier, Umno secretary-general Annuar Musa described Najib as a "baggage" which the party could ill-afford to bear at this point of time.