Canberra - The Brumbies' superb form swayed Andrew Smith's contract decision and convinced him to resist the temptation to take his career abroad for at least one more Super Rugby season.

Smith was one of four Brumbies to commit to the club on Thursday with Jesse Mogg and Scott Fardy signing one-year upgrades and Ita Vaea agreeing to a two-year deal.

Despite suggestions the salary cap will be increased to $4.8 million next year, the Brumbies have signed their players based on a salary cap of $4.1 million.

There is now only one spot up for grabs on the Brumbies' roster for next season with nine players re-signing in the past three weeks.

Up to 19 players will be off contract at the end of next year, but it is understood coach Jake White is already working on new deals to secure his squad for the future.

Smith decided against chasing a multi-year contract to keep his options open.

The hard-running outside centre has cemented his place in the Brumbies' starting XV this season.

He never fielded offers from rival Super Rugby franchises, but turned down approaches from Japan to remain in Canberra.

And his desire to play overseas in the future was the major factor in his decision to back himself to play well enough in the next 18 months to earn a new deal in Australia or abroad.

''It was a little bit tempting for me to go overseas this year, but it's very hard to leave with the season we're having and the way we're building,'' Smith said.

''If you're playing good footy, you'll be rewarded with another contract so that's how I look at it - I've got to continue playing good footy and you'll get what you deserve.

''Going overseas is something I do want to do at some stage but I think it's a bit too soon, I think I can offer something to the Brumbies and Australian rugby.''

Vaea was being pursued by the Waratahs and the Reds, but the Tongan-born No 8 decided his career could move forward in the capital.

Mogg and Fardy have both burst out of obscurity to be Super Rugby regulars this season.

They have been elevated from the extended player squad to the full-time roster and while they have only signed one-year deals, it is believed they have pledged their long-term commitment.

''This is the tightest bunch of guys I've ever played with, everyone is mates and you can see we play for each other,'' Smith said.