The Shoalhaven Rugby Club product, who penned a two-year deal with the Brumbies after two seasons with the Waratahs, enjoyed the first week on the track with his new team.

"It's been good, it's been very tough," Miller said.

"The hard work happens now, and if we can get that in the bank now then it will make it all easier come the end of January.

"It's very tough at the moment but we're all working together and having a good crack - it's great to see everyone is buying in to the common goal.

"There was a wrestling session the other day which was pretty tough, and some of the field sessions have been pretty big which has been good.

"I've got a lot out of them so far, it has been good."

Miller, who helped the Canberra Vikings reach the NRC final last month, is locked in a battle with Tom Cusack and Jahrome Brown to fill David Pocock's position in the Brumbies side next season.

"With Pocock leaving at the time I signed, I was thinking of more minutes," Miller said.

"We've got a great culture down here and I'm looking forward to trying to build on that and help out wherever I can.

"We've got some great players in Cusack and Jahrome [Brown], so I can't wait to compete with them and I've learnt a bit so far.

"The more we compete, the better the team will go.

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"There's a lot of positions up for grabs and a lot of players trying to take them.

"Everyone is trying to prove themselves and we're no different - we're just trying to put our hands up and make ourselves better.

"Jahrome and Cusack are the incumbents, so for me I have got to try to work a lot harder to get that.

"It's competition, and any competition is good competition in an environment like this."

Miller and his Brumbies will open their 2020 campaign against the Queensland Reds on January 31 at GIO Stadium.