Johnson saw comparisons with his own situation in 1996 when he delivered on his promise to unite the 200m and 400m Olympic titles amidst a frenzy of hype.
"He has to make a very solid plan to try to eliminate any distractions. He has had success in Athens and in other competitions so I think he will have to try to duplicate that same type of routine," Johnson said.
"But it will be very difficult to do because it will be a different situation in 2008 in Beijing, so he will have to develop a plan."
Liu became one of China's biggest stars when he claimed the 110m hurdles Olympic title in 2004 and lowered the world record to 12.88 sec in July.
However he has repeatedly claimed about the dizzying media and corporate attention in China, blaming it for a slump in form after the Athens Olympics.
Johnson, who still holds world records at 200m and 400m, said Liu must make sure he maintains his focus.
"He has to make sure that his training and preparation for competitions always come first and that nothing's allowed to distract him," he said.
"If he has a training routine that works for him he has to stick to that routine and not allow distractions.
Liu Xiang in action
"Training and preparation always come first because if he doesn't go out there and perform well because he was distracted, the media's not going to want to talk to him anyway."
Liu will be the focus of massive media attention at the 14-event Shanghai Golden Grand Prix, where he will take on rival Allen Johnson late on Saturday.
Despite his success kick starting a revival in athletics in China, Johnson saw more was needed to halt its global decline in popularity.
"The emerging popularity of track and field in China is certainly a positive, but it can't save track and field and athletics and it can't take it back to the popularity level it had 10 years ago," Johnson said.
"That's going to have to be restored back in Europe and back in America and that's something that's going to have to happen to get it back up to that level. China alone can't do that."
Despite a string of US based drug controversies Johnson maintained he felt it was an international problem rather than being confined to particular countries.
"I think it's a global problem we all face and I think it's just not limited to America or China or any other country," he said.