Manly playmaker Glenn Stewart says he's feeling fresher than ever as he prepares for Saturday's qualifying final showdown with the Sydney Roosters.

Stewart was sidelined for the first six rounds of the Sea Eagles' 2013 campaign due to ongoing concerns with his left knee after undergoing off-season surgery to clean up some cartilage in a troublesome joint.

The back-row star also endured an injury-disrupted 2012 campaign, after breaking a bone in his hand in the opening round of the season.

But the lock said the time off at the start of this year had given his body time properly repair as the Sea Eagles embark on their ninth-straight finals campaign against the minor premiers.

"And definitely mentally fresher (too)," Stewart said on Friday.

"Apart from the weekend I was a bit flat ... but playing half to three quarters of the year has definitely helped.

"Hopefully I can give the boys a bit of a freshen up for the finals."

Geoff Toovey's side travel to Allianz Stadium having lost just once in nine games - that was, before last week's 38-26 stumble against Penrith on Sunday.

"Everyone's had a pretty long year and I think that showed for us on the weekend," Stewart said.

"We were a bit down, a bit flat. And we'll be looking to amp things up a little bit this Saturday."

They will bring with them the spectacular form of their backline that helped demolish Melbourne 28-8 at Brookvale Oval two weeks ago.

Stewart speculated that part of the hiccup against the Panthers could be attributed to other clubs getting wise to their back line's tactics.

"I think it has a lot to do with, if we're having a lot of success on one side, teams sort of focus their defence on that and in turn (that) gives a bit of space to the other side."

Stewart's fullback brother Brett is looking extremely doubtful after missing last week with a hamstring injury, but the Sea Eagles will welcome back Anthony Watmough (knee), Brenton Lawrence (back) and Jorge Taufua (suspension).