Edwin Poots MLA will be stepping down as Minister for the Department of Agriculture, Environment and Rural Affairs.
This will come into effect from 23.59pm on Monday night, February 1, "to facilitate surgery and recuperation", with Gordon Lyons MLA set to take over.
Mr Poots, MLA for Lagan Valley revealed his cancer diagnosis in January.
A DUP spokesperson said: "First Minister Arlene Foster has written to the Northern Ireland Assembly Speaker and nominated Gordon Lyons MLA as Minister for the Department of Agriculture, Environment and Rural Affairs.
"Mrs Foster has also informed the Speaker that Foyle MLA Gary Middleton will take on the responsibilities of Junior Minister in the Office of the First Minister."
First Minister Arlene Foster added: “We give Edwin our best wishes and assure him and his family of our prayers. This is a temporary change, and we look forward to having Edwin back at work, having made a full recovery.”
In mid December, Mr Poots tested positive for Covid-19, although he did not display symptoms.
The former Health Minister also underwent emergency surgery on December 6, to remove his appendix.
