He has recently promised both his people and the international community a clean-up of the country's notoriously corrupt government.
"The president has to introduce [new candidates] before a month is up," said Kabul Parliament member Arfanullah Arfan. "We are concerned that it shouldn't be like it was in the past, when acting ministers spent a long time in their jobs. If this happens again, parliament will take a very serious decision."
Wardak, who has been defense minister for nearly eight years and was previously deputy minister, has strong support from western powers in Afghanistan, and with their help has has overseen the expansion of the army's ranks to over 185,000.
In the 1980s he fought against the Soviet and Afghan government troops as a mujahideen commander. He has also studied in the U.S., and speaks fluent English.
Mohammadi, who also fought as a mujahideen commander, is an ethnic Tajik from the Northern Alliance power block that fought the Taliban in the 1990s and were key to the group's ousting in 2001. He served as chief of staff to the army from 2002 to 2010, before taking up his current job.
The parliamentary vote came days after an Afghan television station reported that the finance minister, Omar Zakhilwal, another minister who has enjoyed the support of western nations in Afghanistan, had stashed away over $1 million (£640,000) in foreign bank accounts.
The report prompted calls for an investigation into Zakhilwal's finances, but he denied any wrongdoing and told the Tolo television channel that the money came from legitimate sources. He had earned up to $1,500 a day as a consultant before taking up his current job in 2009, he added.
Intellpuke: You can read this article by Guardian Correspondent Emma Graham-Harrison, reporting from Kabul, Afghanistan, in context here: www.guardian.co.uk/world/2012/aug/04/afghan-parliament-votes-ministers-out
Additional reporting was provided by Mokhtar Amiri.