The luckless 26-year-old will likely be sent for scans on Monday in the wake of the Brumbies' 26-20 win over the Melbourne Rebels on Sunday.

Tucker grimaced as he came off the field, with the injury set to leave him racing the clock to be fit for the finals series which kicks off at Canberra Stadium on May 1.

It makes the return of dairy farmer Will Miller even more crucial, while Pete Samu will return to the fray for a sudden-death qualifying final. Tom Cusack is also in doubt for the clash.

"I'm not sure if it's a fracture or rib cartilage, but he was in a bit of pain there. We'll see how he pulls up over the next 24 hours," McKellar said.

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"I thought Miller was good, he and Rory Scott in particular gave us a real poach presence and he played a part in that last passage there where we forced a knock-on to ensure we won the game."

Brumbies captain Allan Alaalatoa received treatment on his wrist during the win over the Rebels but is adamant "it's all good" as the title contenders head into a bye before the finals.

"Next week is a great opportunity to review that game and understand where we can get better coming into the semi-finals, but then to also take the opportunity to get away for a little bit," Alaalatoa said.

"A lot of people have put in some great work over the past three or four weeks, staff included.

"It's important we come in over the first couple of days and touch base, understand where we can get better and where to grow, but take the opportunity to spend some time with family before we come in for the business end of the season."