The Jags are 10th in the top flight standings following their 1-1 draw with relegation rivals Ross County and ahead of the visit of Hibs next week.
Alan Archibald's side have just five games to play before the league splits and they will discover their final few fixtures of the campaign.
After Hibs visit Firhill next Saturday, Thistle have away clashes at Inverness and St Johnstone and host Celtic and Hearts inside the next month.
Defender O'Donnell admits it will be a crucial spell as they attempt to haul themselves away from the play-off zone.
He said: "It is the business end of the season now and if we can get another couple of wins from the next five games that would be great and would put us in a strong position going into the split I would think.
"We don't know what the teams around us are going to do, all we can do is look to keep our performance levels up and put points on the board.
"If we don't pick up points and go down the table then it is down to ourselves.
"We just need to focus on ourselves and I am confident that we are capable of getting the results we need between now and the end of the season."
After taking four points from their last two fixtures against Aberdeen and County, Thistle have headed for a training camp in Manchester this week to prepare for their return to action next weekend.
O'Donnell was part of the Jags side that drew in Dingwall after he replaced Jordan McMillan in Archibald's starting line-up, but the 21-year-old won't rest on his laurels after a solid showing at right-back.
He said: "It is frustrating when you are not playing but that is football and when it happens you just need to wait for your chance.
"Fortunately for me that came at the weekend. I did okay but there is room for improvement.
"I think Jordan will be back available for selection for the Hibs game so fingers crossed I play.
"I'm not sure if I did enough on Saturday. We have got a rest this weekend and we will wait and see what happens for the Hibs game.
"There are positives from having a break this weekend. It means we have a rest and hopefully we can hit the ground running again next weekend.
"It doesn't tend to have too much of a bearing but hopefully when we come back we can keep the run going."