Ryder is potentially the only addition to the Power's side that beat the Dockers by 22 points in a semi-final in Perth last season.

But he is also one of the players, along with Angus Monfries, who sat out of the official pre-season games because of their previous history as Essendon players – while the ASADA and AFL supplement investigations ran their course.

But Ross Lyon expects Ryder to be as big a challenge as he has been in the past.

"I don't worry about the opposition that much," the Dockers coach said.

"I know he [Ryder] is playing and we'll have to defend him and he'll be in the ruck and I also know what AFL programs are capable of delivering without them having to have played.

"But they have played a number of intraclub games among themselves, so i don't think he'll be too short [of match practice].

"He's a very talented player and we have dealt with him before. Like all forwards, if they get dirty ball in it's a hard day.

"It's going to be pressure on the ball and up the field [that will be important] for both teams I would image."

That pressure up the field will be a bit tougher for the Dockers to deliver this season, in the early rounds at least, as Ryan Crowley sits on the sidelines awaiting word on his fate – after his own ASADA and AFL investigation into the taking of a banned substance.

Crowley would usually get the job running with Port captain Travis Boak and kept him to just 16 touches and a goal in last year's semi-final.

Robbie Gray is another player who will attract closer attention in 2015 after an outstanding season in 2014. He was right in the middle of the action in the second half of that semi-final, when Port piled on 12.10 to the Dockers' 5.6.

Gray kicked 4.1 for the game and had 21 possessions.

Clancee Pearce is a player that has emerged as the likely replacement for Crowley as the Dockers primary tagger.

"I know [Boak's] a pretty special player," Lyon said

"It'll be a team attitude to all the opposition players. We'll put some time into him. If we think we're just going to roll around and let Travis do what he does, then Travis is going to have a pretty good day.

"We'll get goal side of him, check him, make sure he's made to be accountable and attack him at the right time. There's a lot of stock-standards in AFL footy and that's one of them."

"They're a hard and relentless running team, but we like to think we are too. We know our last quarters rank in the top two or three in the AFL. We know we've had a super summer.

"We've done more work, we've had plenty of room to move. All you can do is prepare yourselves. We'll make some strategic adjustments, but we're going out to play our brand of footy.

"We know it stands up – we've just got to bring it to life."

From the team that lost last year's semi-final to Port, Michael Johnson, Luke McPharlin, Hayden Ballantyne and Pearce have been added.

Fremantle could make changes right up to the final hour though.

Tendai Mzungu was named on a wing in the initial squad of 25, but Lyon confirmed that he was unlikely to play.

"We have a good handle on who has done the work. It can't just be about the last two weeks, if you have missed or not," Lyon said.

"Hayden Ballantyne hasn't played the last two, but he's done 99 per cent of the summer - we have a couple like that. If they get through, they'll play.

"[Michael] Barlow and [Paul] Duffield played (WAFL) last week, so there is a little bit of a decision to be made there, but bona fides who have done the work will play.

"We didn't name a ruckman in the emergencies I don't think, but if you were to lose an Aaron Sandilands or something [in our last training run] you can apply over Saturday or Sunday to have that changed."