The Swans have lost four of their past six matches coming into the clash at Patersons Stadium but after their impressive 24-point win over the Blues, Lyon is under no illusions about the challenge Fremantle faces.
"They were written off last week," he said.
"They were tired and undermanned but all I saw was the reigning premier deliver a powerful performance and they are coming to a ground that they know really well and they like playing at."
"They've been there before. Jarrad McVeigh's led them to a premiership, he's led them through prelims so if we back off for one minute in the game on the weekend, Jarrad McVeigh and the Swans - they'll come over the top of us."
The key to Saturday's encounter lies firmly in the centre square, according to Lyon, after Swans midfielders McVeigh, Kieren Jack and Dan Hannebery were named as All Australians on Monday.
"It is going to be won and lost in the midfield," Lyon said.
"It is where their strength lies. They had three All Australians last night.
"They have got a great ruck combination that matches up well against ours. It is going to be a fierce challenge."
Ryan Crowley was sent to Hannebery in the round eight draw with the Swans at the SCG, only to see Hannebery kick four goals in the opening half.
Lyon says he hasn't decided who Crowley will go to yet.
"We are having a good look at them," he said.
"Sometimes it can be a pain because you can watch too much vision.
"Certainly (Craig) Bird will do a run-with role. (Ryan) O'Keefe will do a run-with, work-off.
"Then you've got the attacking Jack and McVeigh. They can put him back, put him forward.
"They've got some exceptional players. If we just focus on one or two, the rest will get us.
"(Luke) Parker's a unique young talent. We are under no illusions."
Despite the week off the Dockers still have some niggling injury issues.
Garrick Ibbotson has already been ruled out with his ongoing Achilles problem while Michael Johnson, who received his first All Australian honour on Monday, trained lightly on Tuesday but Lyon was confident he would play after missing the qualifying final with a calf concern.
"He is progressing really well," Lyon said.
"We expect him to train on Thursday and be up for selection."
The coach was pleased that Johnson was named All Australian but was unperturbed by the fact that he was the only Docker of the five nominees to be honoured.
"We acknowledged it with the group," Lyon said.
"A good effort. We got him to thank his teammates because they were pretty responsible to help him get that achievement. It is good for the club. It is nice to have an All Australian."
