Speight will play for the ACT Brumbies against the Queensland Reds on Friday night after just two training sessions in a month and less than a week after his efforts at the Sydney Sevens.

The flying Fijian has already dropped four kilograms in a bid to cope with the extra fitness required to play sevens as he targets Olympic selection later this year.

But before he gets there, he has the first five rounds of the Super Rugby season with the Brumbies and is confident his lighter look will be able to cope with the rigours of brutal hits and 80-minute matches.

Speight was 99 kilograms last year as he joined the Wallabies on their World Cup campaign but is down to 94 with a view to potentially go lower for sevens rugby.

"I have to be a bit leaner, cut out some of the chocolates and sweets," Speight said.

"It's a bit of a juggling act, dropping kilos while trying to maintain the strength that's needed for Super Rugby. It's something I'm really working hard at and I think we're starting to get that balance right.

"Mentally it is a bit draining [after playing sevens last weekend], that's probably the big change that I've really found going to sevens as well."

Brumbies coach Stephen Larkham declared spots are up for grabs at Ballymore on Friday as he reintroduces a host of Wallabies stars.

Tom Staniforth, Jordan Smiler and Nigel Ah Wong are all on the bench but impressed in the first outing against the NSW Waratahs last weekend.

Co-captains Stephen Moore and Christian Lealiifano will return to the side with Scott Fardy, Speight and David Pocock.

The clash against the Reds is the last chance to impress before the opening round against the Wellington Hurricanes on February 26.

"Some guys out of the first trial can feel a bit unlucky ... the thought process now is to give the Wallabies a chance to come back in and see where they're at," Larkham said.

"This is our last trial, so we're trying to get as many minutes out of the guys as possible."

Wallabies prop Scott Sio will start on the bench after recovering from knee and elbow injuries sustained at the World Cup.

That opens the door for childhood friend and former Australian under-20s front-rower Allan Alaalatoa to take a chance in the No. 1 jersey and press his claims for more game time this year.

"I'm very excited about the opportunity, going up against [Wallabies tighthead prop Greg Holmes] is going to be a huge experience for me and I'm going to learn a lot," Alaalatoa said.

"I'm looking forward to the battle. Scotty Sio is back a lot earlier than what everyone expected and he's itching to get out there. I think [Larkham] is just going to wait and see ... I got a taste last year at Super Rugby.

"Once you get that, you only want more. The depth is going to push us to be the best we can be."

SUPER RUGBY TRIAL

Friday: Queensland Reds v ACT Brumbies at Ballymore, 8.30pm AEDT. The match will be live streamed at redsrugby.com.au.

Brumbies team: 15. Aidan Toua, 14. Henry Speight, 13. Tevita Kuridrani, 12. Matt Toomua, 11. Joe Tomane, 10. Christian Lealiifano, 9. Tomas Cubelli, 8. Ita Vaea, 7. David Pocock, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Ben Alexander, 2. Stephen Moore, 1. Allan Alaalatoa. Reserves: Robbie Abel, Scott Sio, Leslie Leuluaialii-Makin, Blake Enever, Jarrad Butler, Michael Dowsett, Nick Jooste, Andrew Smith, Tom Staniforth, Jordan Smiler, Nigel Ah Wong.

- The Brumbies will host a meet the players day at the University of Canberra on Saturday from 1pm.