Conservative Councillor for Whittington, Steve Charmley, who along with his role as deputy leader is also the cabinet member responsible for highways – including overseeing Shrewsbury's £81m North West Relief Road – said the decision was due to "ongoing health issues".
The council's leader, Councillor Lezley Picton, said his roles will be split between two of the cabinet's current members.
Councillor Ed Potter, cabinet member economic growth, regeneration and planning, will take over the position as deputy leader – while retaining his current responsibilities.
Councillor Dean Carroll will move from his position as cabinet member for adult social care and public health, to take over the portfolio for physical infrastructure, highways and built housing, which includes highways, housing and assets.
Councillor Carroll's adult social care and public health brief will go to Shawbury Councillor, Simon Jones.
Councillor Charmley said he would be focussing on representing his local community from the back benches.
He said: "12 years in front line politics is hard going. People don't necessarily realise the intensity of it.
"I have given everything I have got for the last 12 years and now it is time to look after myself for a bit and dedicate more time to representing the community of Whittington and West Felton."
It is only four months since Councillor Charmley was one of two final contenders to take on the role as leader of Shropshire Council – losing out to Councillor Picton in a vote of Conservative members.
His brief had included some of the authority's biggest, most complex, and controversial issues.
He had been responsible for overseeing the development of the North West Relief Road, had been tasked with improving the state of the country's roads, and Shrewsbury's potential pedestrianisation plans.
They are all issues which will now fall to Councillor Carroll to navigate – with the Battlefield councillor jumping from the frying pan into the fire having spent the last 18 months dealing with the authority's response to the pandemic as part of his public health remit.
Councillor Picton thanked her deputy for his work, saying: “It was with great sadness that I accepted Steve’s decision to step down from his role as deputy leader and from cabinet, but his health must come first.
"I have really enjoyed working with Steve, he has made good progress with high priority areas such as highways and I publicly thank him for the hard work he has put in.
“On a personal note, he has been really supportive of me in my relatively new role, and I will certainly miss his sense of humour. I wish him all the best."
The changes will come into force tomorrow.