But first Smith wants to ''test'' himself in Super Rugby and says he wants to ''earn my spot'' in the ACT Brumbies squad.

Smith is back in Australia and will train with the Brumbies for the first time on Friday after signing a 12-week contract with his old club. He's making a comeback after retiring from Australian rugby in 2010 and taking his career to France and Japan.

Former Wallabies coach Eddie Jones and Australian captain George Gregan are adamant Smith can be a valuable part of the Test squad for the Lions tour in June.

And Smith hasn't ruled out a Wallabies return if he's called on. ''George Gregan has done it all and Eddie Jones is a mentor of mine, so their opinion, I do take it on board,'' Smith told Rugby HQ on Fox Sports. ''If I was considered for the Wallabies, I'd definitely think about it because it is such a huge occasion. But first and foremost I have to earn that spot and my spot within the Brumbies.''

The 32-year-old is widely regarded as the greatest Australian openside flanker. In Canberra he will team up with incumbent Wallabies No.7 David Pocock, but Smith has spent his time in Japan playing largely as a blindside flanker or No.8.

He looms as a star injection to the Brumbies' line-up for the clash with arch rivals the NSW Waratahs at Canberra Stadium on March 9. That would set up a perfect opportunity for Deans to see Smith play alongside two of his flanker stars - Pocock and Waratahs recruit Michael Hooper.

Smith has played 110 Tests for the Wallabies and 122 games for the Brumbies. He has won every award on offer in Australian rugby and claimed two Super Rugby titles in Canberra. It makes his decision to join the Brumbies intriguing.

Brumbies coach Jake White signed him as a replacement in his squad for the injured Ita Vaea.

''It [the opportunity] was presented to me a little while ago, I had time to think about it and thought it would be a good way to test myself in the Super Rugby arena,'' Smith said. ''I'm pretty excited about the challenge. I've had two good seasons at Suntory Sungoliaths and I think this will definitely test me.

''It's definitely a step up [back in Australia]. I've had a bit of freedom with the way I've played the game in the Top League [in Japan].

''It will be a bit more physical than I'm used to, but I'm up for the challenge … I'd love to play [against the Waratahs], but first and foremost I've got to earn my spot in the Brumbies team.''

The Brumbies' back row has been in form to start the season.

Peter Kimlin, Pocock and Ben Mowen have been outstanding, while Fotu Auelua and Colby Faingaa have added important punch from the bench.

Given Smith's resume´ and record, it's likely White will be able to find a spot for him in the game-day 22.

It's a selection headache White will address over the weekend. He is likely to name his team late next week.

The Brumbies are chasing a hat-trick of wins to start the season and White hopes his team's form and Smith's arrival will attract more than 20,000 fans to the clash with the Waratahs.

If Smith does play, it will be a brutal homecoming for former Brumby Hooper. Hooper was touted as the man who could fill Smith's shoes in Canberra and had an outstanding season last year. But the 21-year-old decided to join the Waratahs and the Brumbies recruited Pocock.

Now Hooper could face a contest with his two idols and two of the best openside flankers in Australian rugby history.