He was hoping the advice would help him win an Olympic medal. He just didn't expect it to be of the gold variety.
But that's what Le Clos had around his neck after a stunning come-from-behind victory over Phelps in the 200-meter butterfly Tuesday.
"He has always been an inspiration to me and a role model," Le Clos said. "I've watched all his races a million times and I've run the commentary over and now I guess I can watch my race."
Phelps has been so dominant in the 200 fly over the past decade that Le Clos wasn't even contemplating contending for victory.
Phelps probably wasn't expecting it either. Otherwise, why would he have offered Le Close free advice last year?
This was supposed to be the race where Phelps became the first man to win the same event at three consecutive games and tie Soviet gymnast Larisa Latynina as the most decorated Olympian of all time.
Well, Phelps got the medal he needed for the record — then got his record-breaking 19th medal in a later relay — but it wasn't the one he wanted.
"Just to be in the final for me was a great honour," said Le Clos, a 20-year-old South African who is competing at his first Olympics. "I didn't really think I was actually going to win the race."
Phelps led nearly the entire race but tried to glide into the wall instead of taking one more stroke. Le Clos made a late charge and took that extra stroke to win by five-hundredths of a second.
"I was on the receiving end of getting touched out," Phelps said. "Chad swam a good race. I've gotten to know him a little over the last year. He's a hard worker, he's a tough competitor and he's a racer."
Le Clos pounded the water when he saw the "1'' beside his name.
"I knew he finished strong and he used his last underwater to his advantage," Le Clos said. "It sounds crazy but I actually thought I was Michael on the last turn. I just felt like I can try to do something special. The last 25 metres actually came in slo-mo."
Phelps hung on the lane rope and buried his face in his hands, disgusted with himself for having squandered what looked like a sure gold. Le Clos won in 1 minute, 52.96 seconds. Phelps finished in 1:53.01, while Japan's Takeshi Matsuda took the bronze in 1:53.21.
It was South Africa's second swimming gold of the games after Cameron van der Burgh won the 100 breaststroke Sunday.
Le Clos won five medals at the 2010 Commonwealth Games as a teenager and took his first major gold at the senior level in the 200 fly at the short-course world championships in Dubai that same year.
Le Clos also won five medals at the 2010 Youth Olympics — where Phelps was an ambassador — and outswam the American and everyone else to win last year's short-course World Cup series.
It was on the World Cup series when Phelps passed on a few tips to Le Clos. The pair spoke regularly and went out for dinner, then met up again this year to shoot an Olympic commercial in Miami. They also kept in touch on Twitter.
Phelps gave Le Clos some more advice Tuesday when the medallists walked around the pool during the victory celebration, telling the South African to "live the moment and enjoy it because it really is special."
But Le Clos isn't done with these games.
He's in the 200 individual medley heats Wednesday, then will face Phelps again in the 100 fly heats Thursday.
"This is the start of something great, hopefully," Le Clos said, also referring to Van der Burgh's win. "We have a fantastic group of swimmers at this Olympics and even in 2016 it's looking positive."
"I really believe the future is bright for us," he added. "The main thing is we have the country behind us this time. We have a lot of support back home. It motivated me."