Thistle slumped to a 2-0 defeat at Dumbarton on Saturday that has left them five points adrift of league-leaders Morton, albeit with two games still in hand.
This latest setback to the Jags' promotion challenge means that Mac's men have now gone four games without a victory, with their last win coming in the 3-2 triumph over Raith Rovers on December 15.
Not since season 2008/09 have the Firhill fans had a title challenge to warm to, when Ian McCall's side pushed a big-budget St Johnstone all the way before being undone by injuries in the final furlong and finishing 10 points adrift of the men from Perth.
Now next up for Thistle is a visit from Steven Pressley's Falkirk on Saturday and McNamara has no doubt about the importance of a return to winning ways if his promotion hopes are not to fade.
The Firhill gaffer said: "It is up to us to learn to handle the extra expectation and pressure that bit better. Right now we are at a stage in the season where every game is carrying added significance and importance and we have to handle that.
"The main problem for us is that we did not take our chances at Dumbarton and it cost us dear. To be fair their keeper had three or four outstanding saves but if we score from any of these chances it completely changes the perspective of the game.
"Instead we conceded from a free-kick and made life very difficult for ourselves. So for the Falkirk game we need to add the cutting edge that was missing at Dumbarton."
However McNamara's hopes of adding to his ranks will not be realised with the completion of Steven Craig's move to Firhill until the end of the season as well as the loan signing of Celtic keeper Glen Daniels the only deals for the Jags.
The Thistle boss confirmed: "No we are not likely to bring anyone else in. It is a case of making the most of what we have."
The last time the Bairns came to Firhill way back on August 11 Thistle handed them a 3-1 defeat with a Kris Doolan double and a Stevie Lawless strike proving decisive. In the reverse encounter a 1-1 draw materialised.
MAC said: "There is no point in looking beyond the next game and that is Falkirk at Firhill this Saturday.
"We started very well against them in the first game at home and that will be important once again.
"But it all comes back to taking your chances. We've been creating a lot of them all season but in the last two or three games, starting with the Boxing Day fixture with Morton, we haven't been taking them.
"It could be a confidence thing with the front two where they are electing to pass rather than shoot but I've said to them that they need to be brave in these situations.
"That applies to everyone. If they want to go up to the next level then they need to be able to handle the pressure of being favourites and take your chances when they come."