United sit fifth in the table ahead of their Friday night clash with Hibernian at Easter Road but McNamara still has not given up hope of finishing second despite Aberdeen's 10-point advantage.
McNamara said: "There's still a lot to play for. I'm sure there will be a few twists and turns between now and the end of the season.
"All we can do is look after ourselves and try and reach the standards we know what we're capable of.
"The good thing is that we've still got to play Aberdeen twice. I know the result went against us on Tuesday night with Celtic losing at Pittodrie. But then again another one went our way with Motherwell losing to St Johnstone.
"There are a lot of games ahead so if we do our job and keep getting the results then second place is still not beyond us."
United have been doing their bit in recent weeks with a 3-1 victory over Motherwell last Friday night securing their third consecutive win.
McNamara believes United are on a roll after their blip over the festive period, and they can move three points behind third-placed Motherwell in Leith.
McNamara said: "Things have been good in the past few weeks and we obviously want that to continue as much as possible.
"This is the kind of game we should be looking forward to because we're going into it having won our last three.
"When you're in the winning habit there's nothing better as a team. I don't think we ever lost that much confidence even when we went through that not so good spell recently.
"But it's always better when you are getting results and we'll go and try to win the Hibs game as we do every match we go into."
McNamara knows Hibs will be a tough nut to crack under Terry Butcher.
"Terry's teams are always hard to play against," he said. "We found that out when he was at Inverness. They are well-organised and well-drilled.
"However, we will focus on what we are good at. We will try and pass the ball around and make things happen. That's what we're good at and will continue to try and play like that."