The top 125 players at the end of the week will advance to the Northern Trust Open, with the top 100 then qualifying for the Dell Technologies Championship, 70 for the BMW Championship and the top 30 for the Tour Championship in Atlanta.
McDowell has to finish in the top 35 at Sedgefield Country Club in Greensboro to move up from his current position of 131st, while Lowry is ranked 145th and needs a first top 10 of the season on the PGA Tour.
Pádraig Harrington will lose his PGA Tour card unless he can produce the second place or victory required to reach the top 125 from his position of 199th, although the three-time major winner will be able to play around nine events next season on a medical exemption after undergoing neck surgery in March.
McDowell has missed the cut in five of his last six events, including last week’s US PGA Championship, and failed to qualify for the Open for the first time since 2003.
But the former world number four, who is currently ranked 110th, is taking a relaxed approach to the week after making the 90-mile journey from Charlotte to Greensboro.
“I feel like I am focused beyond the play-offs and I am into next season already,” McDowell said.
“I am not trying to put too much pressure on myself because it is too late in the season to be putting pressure on myself.
“I feel like I have done a lot of good things this season to have nothing to show for it, so it has been frustrating from that point of view.
“I really like the way I am moving and I have got a great end of year schedule. I go back to Europe and I will probably play British Masters and the Dunhill Links and then come back over here and play two or three of the Fall series and try and get some points on the board.”
World number nine Henrik Stenson is the only member of the world’s top 10 in the field, the former Open champion coming into the event on the back of a tie for 13th at Quail Hollow.
Kevin Kisner, who held a one-shot lead after 54 holes last week but could eventually finish only seventh, will partner Stenson and Bill Haas in the first two rounds this week and has finished in the top 10 in each of his last two appearances in the event.
Meanwhile Ireland’s Leona Maguire has won the Mark H McCormack Medal for the third consecutive year as the leading women’s player in the World Amateur Golf Ranking.
Maguire won the Ladies British Open Amateur Championship at Pyle & Kenfig this season and finished joint runner-up in the 2017 NCAA Championship individual standings.
The 22-year-old from County Cavan, who will shortly begin her final year at Duke University, said: “It’s a huge honour for me.
“To win it once was one thing, but to win it three times is quite a humbling feeling. I know there have been some great names before me but to have my name on there three times is something very special and something that I am very proud of.”
Maguire has won seven times in her collegiate career and finished tied 21st in the Olympic Games in Rio last year.
Elsewhere Brandt Snedeker is taking an “indefinite” break from golf to recover from the rib injury which has kept him out of action since June.
Snedeker, who won the European Tour’s Fiji International last October, withdrew from the Open Championship a day before the first round and hasn’t played since.
The 36-year-old wrote on Twitter: “I would first like to thank everyone for their well wishes over the last few weeks, it has meant a lot to me.
“Unfortunately, I have not progressed in my rehab like we would have hoped and therefore will be shutting it down for an indefinite period of time until I get back to 100 per cent healthy.
“My sternum joint has become unstable and does not allow me to hit a golf ball without pain. My medical team and I are looking into every option to get me back to playing as soon as possible.
“It pains me not to be out there on tour competing, but at this time my health needs to be my priority.”