The Jags skipper has been placed in temporary charge of first-team affairs after McNamara and Simon Donnelly quit to take the reins at Dundee United. And he admits he has no plans to turn into a Firhill tinkerman as the Jags bid to keep their Irn-Bru First Division title hopes firmly on track – starting this weekend against Raith Rovers.
Archibald said: "Most things will stay the same, I will change one or two things here and there, everyone has got their own thoughts on things.
"I want to play the same way and training is at the same high tempo."
The Firhill hierarchy are set to meet tomorrow to discuss a successor to McNamara and Donnelly.
But it is the Jags defensive legend who has the first chance to enhance his credentials for the top job when he leads his troops against Raith on Saturday.
It's a second chance for Archibald to impress after his scheduled dugout debut last Saturday against Cowdenbeath was frozen off.
He said: "The last few days have been good. It was disappointing that the game was off on Saturday.
"The players were buzzing for it and there was a good feeling among the fans as well.
"We wanted to get on and get a game under our belts but it wasn't to be. We would have got a good backing from the fans, from what I hear they were going to go in their numbers.
"It would have been good for to us to get the game on. I had everything set up and the boys were raring to go.
"We were coming off the back of two good results against Falkirk and Cowdenbeath and were confident of going there and winning. I had a couple of things in mind that I wanted to do but not much. Nothing has changed, it is just a different voice."
Having been denied the chance to make his managerial bow at Central Park, Archibald has spent this week organising his side for a crucial First Division fixture as Thistle look to keep up the pressure on leaders Morton.
The exit of McNamara was an untimely blow to the Jags as they enter a crucial run of games that could shape their promotion dreams.
And Archibald, assisted by former favourite Scott Paterson, hopes familiarity will breed success. He said: "I watched Raith against Celtic last weekend and the pitch wasn't great.
"We might change one or two things that might affect the team and the shape, but I am sure we have got enough there to win the game.
"I had my mind made up about playing or not, but I will keep that close to my chest and see how the week's training goes before I divulge my plans.
"I don't want to tell anyone what we have got planned before we name the team.
"The big thing we want to change is our away form. It has been a problem and we want to sort that out."