The Swiss government could also do more to prod Zurich-based FIFA to change its ways, Pieth added during a presentation to the "Play the Game" conference in Aarhus, Denmark, on Wednesday.
"It's bit of a sad story that the sponsors haven't come out more forcibly and I think we should encourage them to do so," Pieth said.
"My suggestion to the sponsors would be to take this governance reform very seriously."
However, Pieth said that recent events in Brazil, which is hosting the 2014 World Cup, may have forced sponsors to think differently.
The Confederations Cup, a dry run for next year's tournament, took place amid a wave of nationwide protests in Brazil where the cost of hosting the World Cup was among the causes of public anger.
"I think for the first time in Brazil, they have realised the buying (sponsoring) of such an event can also turn to a disadvantage....if you're name is associated on television with unrest all the time," said Pieth.
He said Switzerland could do more simply by ending tax-exempt status.
"The host state could require a certain minimum in governance (standards)," he said.
"You don't have to change a single or law or this status of these companies. If you cannot judge whether they're non profit, you cannot give them tax-exempt status."
"The consequence could be that they will flee the country, they will run away but tough luck. That is what the state needs to do."
"With FIFA, you have the difficulties that the world is facing vis-a-vis corruption and you have a patronage network of people who believe they are in a private environment," added Pieth.
"You don't have to go so far to realise this. If you go to southern Europe, you have fantastic football nations, one after the other. But they are not very enthusiastic about this reform process and would rather ditch it sooner than later."
However, he said the recent changes to FIFA's executive committee could eventually lead to reform.
"Between one quarter and one third of the executive committee has been changed," he said.
"Many of the new people are champions of this governance movement, they want to see change and that will bring about change."
Some of Pieth's suggested reforms have been implemented, including the establishment of an independent ethics committee as well as an audit and compliance committee.
However, FIFA has failed to implement other proposals including restricted mandates and age-limits for senior officials.
"There's a lot more happening that we might be seeing," said Pieth. "It takes time, it's a long-term project."
- Sports & Recreation