The Brumbies will give Nick Jooste, Isaac Thompson and Wharenui Hawera a chance to impress in the flyhalf role after starting their Super Rugby preparations.

The Brumbies have named Lealiifano in a 37-man squad but the regular skipper is unlikely to play any role in the 2017 campaign as he continues his fight against leukaemia.

Brumbies prop Ben Alexander said Lealiifano's health battle would act as extra motivation for the players as the popular leader continues treatment in Melbourne.

Lealiifano's absence and Toomua's move to England means the Brumbies need to find someone to take the on-field reins and call the shots.

Recruit Kyle Godwin made his Wallabies debut last weekend and will offer inside centre options with Super Rugby title winner Anthony Faingaa.

But the No.10 duties will likely fall to an untested rookie with teenager Jooste the only specialist flyhalf on the Brumbies' full-time contract list.

Thompson is trying to make the step up from the National Rugby Championship while Hawera has been given a training deal to prove his worth.

"There is a spot up for grabs in the [flyhalf] position specifically," said interim coach Dan McKellar.

"Wharenui is a New Zealand boy and has played for Waikato and Southland, he's a good young footballer.

"Then there's Isaac Thompson, who we're familiar with as well and he's training well. [Thompson] is a smart footballer, he identifies space well and has good speed.

"[The circumstances] are out of our control and it's not ideal but we've got a couple of options and we'll go about picking the right one."

The Brumbies have all but finalised their search for a new chief executive with an announcement on the role likely to be made this week. Michael Thomson is believed to be the front-runner for the position.

The Brumbies were put through an intense breakdown session on Monday morning as the first full week of training started in hot conditions.

There were more than 10 new faces trying to make their mark, but it's the thoughts of inspirational leader Lealiifano that will drive the players, according to Alexander.

The Brumbies have turned to an eight-man leadership group to take control in the absence of captain Lealiifano and Stephen Moore.

Lealiifano had a bone-marrow transplant last week and is staying in Melbourne for more treatment after being diagnosed with the blood cancer.

Lealiifano will likely take a coaching role with the Brumbies backline and young playmakers if he is unable to play this season.

"We miss him and we can't wait to get him back," Alexander said.

"His whole attitude to this has been unbelievable and that's inspirational. If we can't have him on the field, he's still our leader.

"When you're facing something [Lealiifano] is facing, you see things incredibly clearly. We're fortunate to get to play rugby.

"Even though we might hate it a bit when we're out there in the sun getting flogged [in fitness sessions], it's nothing compared to what he's dealing with at the moment."

Returning hooker Saia Faingaa trained with the Brumbies for the first time on Monday, completing a full career circle eight years after the Queanbeyan junior left the capital to join the Queensland Reds.

Faingaa's twin Anthony will also make his Brumbies comeback in January after he completes his playing commitments in Japan.