The 30-year-old has enjoyed a stellar campaign in Canberra, working in tandem with Sio and faces his former club on Saturday in the final round before finals.
Slipper hasn’t played for the Wallabies since 2017, but on current form the 86-Test prop is a near certainty to feature at his third World Cup in September.
Sio is fighting Slipper for the Wallabies No.1 jersey but said his teammate deserves to be in the World Cup squad, having served his time for past indiscretions.
“He hadn’t played a lot of rugby the last two years before coming here with the injury in 2017 and a bit of adversity last year,” Sio said.
“Unfortunately for Slips it’s something that’s always going to hang around but he’s moved on with his life and he’s put his best foot forward here in Canberra.
“It was great for him to come here and challenge himself in a new environment, after all he went through it could have been easy for him to stay up there in Queensland and just see things out. But he chose to take the tough road and it’s paid off for him this year.
“If you’re playing the best and you’re available you should be up for selection.”
Brumbies tighthead Alaalatoa echoed the sentiment and said the front-row rotation between Slipper and Sio helped the club win back the Australian conference this season.
“It’s been huge for us, the rotation, they’ve never had that at the Brumbies, Scotty has always been that No.1 loosehead who has played 70 minutes,” Alaalatoa said.
“Slips coming to Canberra has helped him a lot and he’s helped me as a player and the other young props.
“We see the type of footy he’s playing which is probably the best footy I’ve ever seen him play.”
Watch: Allan Alaalatoa and the ‘big dog
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