Millers beat Moorlands Railway at the weekend, while Rustons take on Dynamo Rileys and Clifford believes it will be the Premier sides who reach the Semi finals rather than their lower league opposition.
However, the Welton forward is well aware that Welton will have to contain the threat of a few former Stags players.
"It's really bad news for us," Clifford told the Welton news. "I admire the Stags lads they were a great team and individually they are all still tough opposition.”
"If you give them half a chance in the area they will take it.
"It's going to be a very tough match, they are a physical side. And against lower league sides it's always hard because they want to take a premier league scalp especially now as we are one of the best four teams in the County.
"If Welton don't find our feet, don't score a goal, we will be risking a lot.
"We have to score early on, and especially not concede, so we can play our own passing game.”
"To beat Swan, Welton have to put the maximum effort in."
He added: "If I had to bet though I think it will end 3-0 to the Premier sides. Welton, Millers and Rustons will all progress along with Nettleham.
"Just look at history. But anything can happen."
