Sydney - The Waratahs will react to their embarrassing loss to the Brumbies by making up to seven changes, including the promotion of Sarel Pretorius and the demotion of Tom Carter, for Friday's game against the Bulls at Allianz Stadium.

After wasting so many early attacking opportunities in Canberra, the Waratahs selectors have no option but to revamp their midfield, with Daniel Halangahu in contention to replace Carter at inside centre, while Rob Horne will return to outside centre after returning from suspension.

It is understood the Waratahs selectors were pleased with Halangahu's performance off the bench last weekend, believing he can provide better support for flyhalf Berrick Barnes, who played a more direct game, regularly attacking the gainline with ball in hand. Halangahu's involvement will give the Waratahs two midfield distributors.

After starting five games on the reserves bench Pretorius, the Waratahs' marquee overseas signing, is due for a recall to the starting line-up at the expense of Brendan McKibbin, which is not surprising, as the former Cheetahs halfback intimately knows what to expect from their South African opponents. McKibbin - who has provided the Waratahs with consistent goalkicking - and Carter both ran with the backup squad at yesterday's training session at Moore Park.

While fullback Bernard Foley ran on Monday, it remains doubtful he will be available because of his shoulder complaint, and it will be a few days before the selectors know if wing Tom Kingston, who appeared at outside-centre in Canberra, will play due to a hamstring concern.

The Waratahs pack will also have an overhaul. Openside breakaway Chris Alcock returns after having his appendix removed, and captain Rocky Elsom is preparing for his first starting appearance of the season. Although blindside breakaway Dave Dennis was one of the Waratahs' best in Canberra, the selectors know it is time for him to have a break. Although Dennis ran with the team on Monday, and Elsom was among the onlookers, a No 6 personnel change is imminent.

Wallabies hooker Tatafu Polota-Nau is likely to miss the Bulls match after suffering several serious head knocks against the Brumbies. While the Waratahs remain hopeful Polota-Nau will be available, they will not risk him, and John Ulugia was on Monday preparing as if he was about to take over as run-on hooker. A second row alteration is also probable.

Coach Michael Foley said the team on Monday reviewed their 17-point Canberra loss, and it wasn't pleasant. ''We're pretty disappointed by what happened. Then today we reviewed the game and were reminded of some of the things we set up for ourselves in that game and didn't finish off,'' he said.

The Waratahs, nine points behind the Brumbies at the top of the Australian conference, must win their next three encounters - all against South African teams - including two in the republic - to stay in touch. But they know the dangers of looking too far ahead.

''Every team wants to play in the finals, and every team wants to win the competition. Whether those things are a reality for us is not for us to think about right now,'' Foley said.

''We just have to play as well as we can in every game we play. Look at how we started against the Brumbies with the ball in hand - it was very positive. We were challenging and breaking the line. But we didn't finish off those chances. Now it is about creating those opportunities against the Bulls, and this time finishing them off.

''If we start thinking about what's going to happen at the end of the year, we'll take our eye off the ball right now.''