The worker said his wages were docked by £700 due to his three-week absence.
He fell sick in January - the same week that two of his colleagues, both lorry drivers, sadly died after testing positive for the virus.
"I've never felt so ill. It totally floored me. I just there feeling terrible there with every part of my body aching and thinking of my colleagues who had died," he said.
"The doctor said to stay off work for three weeks and then stay at home a fourth week if I still felt ill. But after three weeks I went back. I knew 40 per cent of the lads were off, either ill or self-isolating, so I wanted to help.
"I was still suffering with post viral fatigue, but I managed to work."
When his wages came last week, the worker expected around £2,000. He'd worked hours of overtime because of staff shortages and had also gone in on a Saturday to help clear the city's backlog of rubbish.
"I couldn't believe it when my wages were £700 short. I'd been docked the three weeks and paid statutory sick pay of £95 a week instead," he said.
"I have children to support and rent to pay and it left me really short."
The workers fears his colleagues may be tempted to work when they have Covid symptoms or decide not to self-isolate if they've been in contact with the virus - because they are worried about losing money.
"You'd think a company making that much money would pay their workers properly when they get Covid, particularly as they've probably caught it from work," he said.
"I rang Serco pay roll department and they said that I wont get payed the £700 and they stand by their decision as they pay alongside government advice."
We contacted Serco to for a response to the worker's comments and claims.
Mark Sturgeon, Serco's Senior Contract Manager, told us the company is making improvements to its policies related to Covid.
"We have made a number of enhancements to our absence policies for employees who are unable to work for Covid related reasons, including where employees need to isolate or shield," Mr Sturgeon said.
He added: "Currently no employees have made us aware of any issues. However if anyone in my team is experiencing hardship I would urge them to speak to their line manager so we can look at what measures can be put in place to assist them.”