The Waratahs have recalled giant lock Will Skelton after missing the past two weeks with a hamstring injury, but playmaker Bernard Foley has been ruled out as he continues to battle concussion symptoms.

The Brumbies are still stinging from a 53-17 loss to the Waratahs in a pre-season trial last month.

Skelton is a massive inclusion and the 140 kilogram beast is the key to NSW stopping the Brumbies go-to move of a rolling maul.

Skelton will partner lineout general Dean Mumm in the second row, setting the stage for Brumbies skipper Sam Carter and Rory Arnold to go head to head in an all Test battle.

"You've just got to get in Will's face and defend as a team, if we can counter all of their threats we'll go a long way to winning the match," Carter said.

"It's a big game and big responsibility, any time you play the Waratahs there's no extra motivation needed. Nothing comes easy."

NSW linchpin Israel Folau is also searching for form at outside centre, and the cross-code superstar has scored three tries in his past four games from the Brumbies.

But conditions may dictate Folau's involvement, with Sydney's wet weather to favour a set-piece showdown.

"The Waratahs are a dangerous attacking side, either way we're going to be in for a tough game," said Brumbies coach Stephen Larkham.

"Have you ever seen [Folau] have a bad game? He's a consistent performer and is relishing his chance to get his hands on the ball."

SUPER RUGBY ROUND FOUR

Saturday: NSW Waratahs v ACT Brumbies at Allianz Stadium, 7.45pm. To donate to the Brumbies' World's Greatest Shave, visit: http://my.leukaemiafoundation.org.au/brumbies

Brumbies team: 15. Aidan Toua, 14. Henry Speight, 13. Tevita Kuridrani, 12. Kyle Godwin, 11. Nigel Ah Wong, 10. Wharenui Hawera, 9. Joe Powell, 8. Jordan Smiler, 7. Lolo Fakaosilea, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Allan Alaalatoa, 2. Josh Mann-Rea, 1. Ben Alexander. Reserves: 16. Robbie Abel, 17. Nic Mayhew, 18. Leslie Leuluaialii-Makin, 19. Blake Enever, 20. Ben Hyne, 21. De Wet Roos, 22. Jordan Jackson-Hope, 23. Andrew Smith.

Waratahs team: 15. Andrew Kellaway, 14. Reece Robinson, 13. Israel Folau, 12. Irae Simone, 11. Rob Horne, 10. Bryce Hegarty, 9. Nick Phipps, 8. Jed Holloway, 7. Michael Hooper, 6. Jack Dempsey, 5. Will Skelton, 4. Dean Mumm, 3. Sekope Kepu, 2. Tolu Latu, 1. Tom Robertson. Reserves: 16. Hugh Roach, 17. Paddy Ryan, 18. David Lolohea, 19. David McDuling, 20. Ned Hanigan, 21. Michael Wells, 22. Jake Gordon, 23. David Horwitz.