The Reds are sweating over the fitness of star flank Liam Gill, but veteran lock James Horwill looks set to return to face the Bulls in a crunch match.

The Reds have a huge week coming up, with the Bulls in town on Saturday and both teams looking to bounce back from disappointing defeats last week.

Reds Director of Coaching Ewen McKenzie said the Reds would need to learn from their 12-19 loss to the Western Force as they prepare for the Bulls.

"I'm still waiting for the whole team to fire," McKenzie said.

"As I said last week, we've still got plenty in us and we certainly didn't put it out there [against the Force].

"So, I guess it's this week we'll be looking for it."

However, it is the return of Horwill, who captained them to Super Rugby glory in 2011, that will delight the Reds most.

"James [Horwill] is also looking pretty likely after getting through training this past week," McKenzie said of the veteran who has been sidelined with a succession of hamstring and ankle injuries.

However, the Reds are holding their breath over the fitness of Gill, who will have to undergo scans on his knee - with fears that he has done his medial ligament some damage.

McKenzie said he did not believe the injury was too serious, but booked Gill in for scans to ensure he would not break down against the Bulls.

If Gill is ruled out, Jake Schatz would likely move from No.8 to No.7, with back-up openside Beau Robinson (ankle) also sidelined.

Back row replacement Radike Samo is another doubt for the Reds, as he also struggles to overcome a knee complaint. Young Jarrad Butler is on standby to make his starting debut.