The 72-Test Wallaby and most-capped player in Brumbies history made a low-key retirement announcement on Monday. No fanfare or farewell tour in Super Rugby. Just an understated goodbye after 10 years at the top.

Alexander played 154 games for the Brumbies, passing the records set by Australian rugby greats George Gregan and George Smith to be at the top of the list.

But the 33-year-old was just happy to earn one cap, especially after a broken leg and blood clot from complications threatened to ruin his professional dreams.

"Never in my wildest dreams did I ever think I would be good enough to play a game for the Brumbies or Wallabies," Alexander said.

"I just kept playing every weekend because I enjoyed the game so much. So I guess what I've taken most out of this whole journey is to just give what you love doing your best shot, even if you don't think you're good enough ... you might just surprise yourself."

Alexander burst on to the Super Rugby stage as an unknown front-rower when he made his Brumbies debut from the bench and scored a try with one of his first touches.

Within three months he made his Test debut for the Wallabies, earning his first cap for Australia before he'd even managed to force his way into the Brumbies starting team.

From there it was a wild ride of 72 Tests, including the 2011 World Cup, the highs and lows of Super Rugby and transforming from young buck to respected bookend.

Laurie Fisher was the coach who called Alexander up for Brumbies duties when he was on an academy contract in 2008.

Fisher has been around the world since that moment, coaching in Ireland, returning to the Brumbies, moving to England and then coming back to the Brumbies again.

The only two players who are still at the Brumbies since Fisher was head coach in 2008? Alexander and Christian Lealiifano.

"Through the whole time, I've really admired Benny because he's a great clubman," Fisher said.

"His desire for the Brumbies to do well, his desire to win a Super Rugby championship here ... he had no ambition to go anywhere else. All he wanted was for this team to be successful.

"He has always been selfless with the way he's managed himself around the Brumbies environment."

The Brumbies and Alexander, a father of three, have been speaking since the end of the season about his long-term future and whether he would continue playing in 2019.

In the end Alexander sent a message to family and friends saying his "time has come" and he was retiring from professional rugby.

The likeable and versatile prop was a fan favourite until the end in Canberra, playing nine games in his final season.

His on-field role changed over the years. At one point Alexander was a try-scoring machine, crossing the line seven times in 2010 to be the club's top try-scorer. In that season he played all but for four of the 1040.

Alexander became a mentor to current Wallabies Scott Sio and Allan Alaalatoa, helping usher in a new generation of props.

"He's always done what's best for the team. He'll be remembered at one of the greats at our club," said Brumbies coach Dan McKellar.

"His enthusiasm, his energy, his knowledge ... whether BA was in the game-day 23 or the starting side, he was always committed to the team. You always respected his opinion and he'll be remembered as a great team man.

"That says a lot about his love for the Brumbies. He was happy to pass on his knowledge and experience, his attitude and commitment ... his want for the Brumbies to do well has always been at the front of his mind."

Alexander will finish his playing days as one of the most respected players in Super Rugby and one of the most-loved by fans. He also played 72 Tests for Australia and is one of the most-capped front-rowers in Australian history.

The Brumbies will pay tribute to Alexander at the club's presentation night on Friday and chief executive Michael Thomson said the prop deserved his place among the greats.

"He's been great for us on the field. To play 154 games in such a challenging position, and the way he's played, has been fantastic," Thomson said.

"On the field, you wouldn't get a better clubman. I'm sure there were chances to chase money in Europe or Japan at different points.

"To start and finish as a one-club player, it's a reflection of him as a person. He's played all of those game and nurtured a whole lot of young players coming through. We'll miss him, but I'm sure he won't be a stranger to us."

Alexander is only the fifth Australian player to reach the 150-game milestone in Super Rugby.