Flanker David Pocock posted a photo of Lomu with his arms around him and winger James O'Connor in Wallaby training gear.
"Great to meet the legendary Jonah Lomu. What a good bloke too," Pocock tweeted.
O'Connor said Lomu was "one of the most genuine blokes I've met".
Australian coach Robbie Deans was Lomu's last backs coach for the All Blacks, and the famous number 11 met up with the Wallabies after their 2009 Bledisloe Cup match in Tokyo.
He has been in contact with Deans since and will have dinner with the Wallabies at their hotel tonight.
Last month, Lomu was admitted to Auckland City Hospital and is undergoing tests to see if his failing kidney can be revived.
The 36-year-old played a key role in the World Cup opening ceremony on September 9 and appeared healthy.
But days later, he struggled to hold down his food - a problem that persisted for 10 days.
He was rushed by ambulance to hospital on September 23 after struggling with nausea and weight loss.
A kidney that broadcaster Grant Kereama donated to him in 2004 was believed to be shutting down.
If Lomu's body rejects that organ, he might face a wait of up to eight years for a new donor.
He is now on daily dialysis.