Dr Hafeez Shaikh, the former finance minister, tested positive for COVID-19 Tuesday.
Newly appointed Finance Minister Hammad Azhar gave the update Dr Shaikh's health on Twitter.
He said he had "just found out that Dr Hafeez Sh has tested positive for Covid-19".
"I pray for his swift recovery and good health. Ameen," Azhar wrote.
The federal government removed Shaikh and appointed Azhar as the new finance minister a day earlier.
There was reportedly some resentment among government ministers on matters of taxation and bill-granting autonomy to the State Bank of Pakistan.
The prime minister had reportedly conveyed to Shaikh to step down from his role.