"He never trained quite as hard as he needed to," Foster said. "[All Blacks fitness coach] Nick Gill was our trainer at the time and he was almost full-time getting Sione fit, but he helped change the whole way we played and turned us into an open, fast, exciting team at the time.
"He never really pushed himself as hard as he could off the park to be the best on the park. But there were moments each year when you just couldn't stop him. Most people have unique memories of him demolishing opponents almost single-handedly."
Israel Dagg, who played alongside Lauaki for the All Blacks, was one of those who recalled him dominating an opponent at the collision - and not just any opponent.
"He was an absolute legend," Dagg told Newstalk ZB. "He was a quiet man, but on the field, he was dominant. I've got this video in my mind of when he absolutely threw Richie McCaw 10 metres. He was a big man with a big heart and had a lot of time for everyone."
Born in Tonga, Lauaki emerged out of Kelston Boys' High and debuted for Auckland in 2002, before switching to Waikato and making his maiden Super Rugby appearance for the Chiefs in 2004. He first pulled on the black jersey a year later in a victory over Fiji and was eventually part of the All Blacks squad that fell short at the 2007 World Cup, but found his path at the top level blocked by Rodney So'oalio and Jerry Collins.
Lauaki also played for the one-off Pacific Islanders combination and, within a 15-day period in 2004, scored tries for them against Australia, New Zealand and South Africa.
After playing his last Super Rugby match for the Chiefs in 2010, Lauaki made 51 appearances for French club Clermont before finishing his playing career with 16 games at Bayonne.
While undergoing routine tests in France, Lauaki discovered he was suffering from renal failure and cardiovascular problems, prematurely curtailing his rugby career. He then returned to New Zealand before getting married in Rarotonga in 2014 and living there since.
Lauaki's death led to an outpouring of grief in the rugby community, with a number of players taking to Twitter to pay tribute.
Sonny Bill Williams told Lauaki to "rest easy", tweeting, "Damn. It's a sad day today", while Nick Evans posted an image of him being tackled by Lauaki and said, "Gutted to hear the passing of Sione Lauaki. He got me a few times, but a honour to play alongside you in the All Blacks brother."
Sione Lauaki
• Made his test debut off the bench in the All Blacks' 91-0 demolition of Fiji at Albany in 2005.
• He went on to play in all three tests against the touring British and Irish Lions that year.
• Injury ruled him out of All Black selection in 2006, but he returned as a World Cup contender when he starred for the Chiefs in a victory over the Crusaders in Christchurch with a phenomenal fend on Richie McCaw.
• Lauaki played 17 tests for the All Blacks between 2005 and 2008, scoring three tries.
• Before his All Blacks debut, Lauaki scored test match tries for the Pacific Islanders against Australia, New Zealand and South Africa within 15 days in 2004, a feat without precedent.