Peter Sterling believes the Penrith Panthers have a major ace up their sleeve ahead of their sudden death semi against the Brisbane Broncos at Suncorp Stadium this weekend.

Sterling said the return to form of classy forward Bryce Cartwright could be the missing ingredient for the mountain men.

“I thought the two big plusses were Dylan Edwards at fullback basically stepping out of a leg brace to play and Bryce Cartwright who has looked really inhibited since coming back from injury,’’ Sterling said on the Wide World of Sports website.

”He didn’t look confident on that leg. Coach Anthony Griffin said that the last twenty minutes against Manly the previous weekend [Round 26] was really a good sign.

”To score two tries and be involved in the other one, that’s huge for them, because he can be a real X-factor for them.

”He’s had a mixed season, we haven’t seen his best football by any stretch of the imagination, maybe he’s on the verge of something a little bit special again this weekend.”

The Broncos will start favourites against the Panthers after a narrow defeat to the Roosters last weekend.