Though it seems hard to believe now, when you see the all-action Popoali'i skipping and jumping around the rugby field, he was once affected so badly by a bad heart he could barely stay awake during the day and was confined to a wheelchair.
Popoali'i (23), the Highlanders winger, is like Fruean in that he caught rheumatic fever at an early age, and was forced to go under the knife at just 16.
Crusaders centre Fruean had a heart valve installed in 2009 as he tried to overcome problems with his heart caused by rheumatic fever.
It was announced last week Fruean (24) would take an indefinite break from the game as he needed to get a new heart valve installed. He had the surgery on Wednesday in Christchurch.
Popoali'i had been in contact before the operation to wish Fruean, who had been struggling for fitness over the past six months, all the best.
Unlike Fruean, Popoali'i has been well since he had an operation in 2006.
Popoali'i said his problems began at a young age as he started losing energy.
''I would feel awesome in the morning but then in the afternoon I was starting to feel really tired. Then I went to live in Australia for a while but it didn't really change,'' Popoali'i said.
''When I came back to live in Wellington from Australia they had to bring me in a wheelchair at the airport. They didn't know what was wrong with me there for a while.''
Eventually, it was discovered he was suffering from rheumatic fever, causing an inflammation of the heart muscle.
An operation was needed, which would insert a pig valve into his heart, and make the heart operate better.
He was in hospital for three months after the operation, making a slow recovery.
It did not take long to get back on the rugby field, and he went on to make his first-class debut in 2008, his first year out of school.
He has never been troubled by heart issues since the operation.
''I get a jab once a year and I also have to take a couple of pills every day. They help keep the germs and that away from the bones.
''I have been fine ever since. Never felt any problems. The valve is supposed to last for 30 years, so it should be fine.''
Popoali'i knows Fruean well - they both grew up in Wellington, and are about the same age - and is in contact with him.
''It is pretty sad what has happened to him. I can just imagine him, running hard and straight in the black jersey, if this hadn't happened to him.''