That's the question facing the ACT Brumbies after David Pocock signed a new flexible deal that will see him take a sabbatical next year before returning for the 2018 and 2019 Super Rugby seasons.

Lucky for the Brumbies they've been in this situation twice in the past four years and are set to open the door for a young gun to make his mark in Pocock's absence.

Pocock will leave a sizeable hole in the Brumbies' line-up when he puts his career on hold at the end of the year to step away from the game to refresh and recharge.

The superstar openside flanker missed back to back years in 2013 and 2014 after having two knee reconstructions and managing just five games in that period.

Brumbies champion George Smith stepped up to replace Pocock in 2013 and Jarrad Butler the following year, and the Brumbies believe they've got the depth to cover Pocock's temporary absence as well as targeting a future star.

The Brumbies are unlikely to pursue Smith, who has a contract to play in Japan, or former Queensland Reds No.7 Liam Gill to fill the void.

Instead Butler, who is in negotiations with Brumbies management about a new deal, Jordan Smiler and Michael Wells will have chances to shine and the club could opt to recruit a player for the national under-20s competition.

"We've got guys who are here next year and it gives us an opportunity to look at some young up and comers as well," Brumbies chief executive Michael Jones said.

"Between Ita [Vaea], Jordan, Butler, Scott Fardy and Wells we've got a pretty good back row in reasonable shape."

Pocock's No.1 focus is helping the Brumbies chase an elusive title this season before taking a 12-month sabbatical.

The Brumbies are also looking for an extra hooker to add to their books to cover the loss of Wallabies captain Stephen Moore as well as an inside back to add midfield punch.

Moore, Pocock, Matt Toomua and Joseph Tomane have all confirmed they will not be at the Brumbies next year, but the club has started to lock in the future with a host of re-signings.

Pocock will play 2018 and 2019 while Christian Lealiifano, Scott Sio, Allan Alaalatoa and Joe Powell have signed new contracts.

Pocock, 27, said he wanted to stick by the Brumbies after the club put faith in him following two knee reconstructions in two years limiting him to just five games.

It's a massive boost for the Brumbies in the build-up to their clash against the Cape Town Stormers on Sunday morning as they aim to keep an unbeaten start to the year.

"It's great to sign on until the end of 2019 and get it out of the way so we can focus on Super Rugby," Pocock said in Cape Town.

"I've loved the last four years in Canberra and at the Brumbies. It was a tough couple of years [when I injured my knee] and they stood by me and I got a lot of support. I feel like that's where I want to play my rugby."

The Brumbies have won their first three games of the season and sit at the top of the overall ladder.

They play the Stormers in the first of two games in South Africa before taking on the Free State Cheetahs next weekend.

SUPER RUGBY ROUND FOUR

Sunday: Cape Town Stormers v ACT Brumbies at Newlands, 4.15am (AEDT). TV time: Live on Fox Sports 2