McNamara completed his first signing as Jags boss last week with the capture of St Johnstone left-back Johnny Lindsay.
Thistle's resources were stretched in the closing weeks of the campaign as almost an entire team of players found themselves sidelined.
But the Firhill gaffer is aiming to keep his group motivated as they battle on with what they have at their disposal.
"I don't want to bring in too many players," McNamara said.
"I don't want to have five or six guys sitting in the stands every week.
"We have younger guys who can play their part, like Jamie Campbell did last season.
"When you are working to a tight budget, it is important that you have players who can adjust."
While McNamara hopes Lindsay will be able to make an impact in the first team straight away, at 19, the former Saints star is also one for the future.
McNamara said: "I think Johnny is an exciting signing for us, he has a lot of potential and hunger to do well.
"We have Alan Archiebald signed up and hopefully we can sort something out with David Rowson.
"I am keen to get Tommy Stewart signed up as well. He showed at the end of the season what he could do and that he can score goals."
O'Hara catches the eye
Wishaw hero Paul O'Hara said he almost quit the game before helping his side lift the Scottish Amateur Cup.
O'Hara saved four spot kicks as Wishaw lifted the trophy for the first time with victory over Drumchapel.
After the game ended 1-1, with goals from Alan Patrick and Alex Crearie, Wishaw ran out 3-1 winners in the shoot-out. O'Hara said: "I was thinking of giving up as I was going nowhere, but now I can't wait for next season."