ATLANTA -- It's decision day all around MLS.
While Atlanta United FC has already clinched a spot in the playoffs, Sunday's game against Toronto FC will help determine which seed the Five Stripes will get heading into the postseason.
If the playoffs started today, the Five Stripes would be the No. 4 seed in the east and host a single-elimination knockout game. However, they can move up as high as No. 2 and as low as No. 5 depending on how Sunday's slate of games turns out. Toronto has already clinched the No. 1 seed and is the Supporter's Shield recipient.
The top two seeds receive a bye in the first round before hosting the conference semifinals. Unfortunately for Atlanta United, the stars must align for them to move up to No. 2
To move up to No. 2, Atlanta United would have to beat Toronto AND NYC FC draw or lose to Columbus Crew AND the Chicago Fire draw or lose to the Houston Dynamo. That's all possible, but the odds aren't really that great.
For Atlanta United to move up to No. 3, the Five Stripes would need to win and Chicago would need to lose to Houston. The No. 3 seed faces the No. 6 seed, and the No. 4 seed faces the No. 5 seed.
Atlanta United stays where it is at No. 4 simply with a win (assuming the other scenarios don't happen) or if Columbus loses. If both Atlanta United and Columbus lose, the Five Stripes stay at No. 4.
If Atlanta United draws, Columbus would need to win to move up to fourth. Atlanta United also drops down to No. 5 if they lose and Columbus wins or draws.
Atlanta United would love to be No. 4 or higher (which they will be with a win) so they can host a playoff game at Mercedes-Benz Stadium. They are 5-1-1 at Mercedes-Benz Stadium. The first round is Oct. 25 and 26.
But a win isn't guaranteed. Toronto is the top team in the east and is attempting to set a points record on Sunday. They have a strong attack from the likes of Sebastian Giovinco and Jozy Altidore. They have 29 goals combined.
Atlanta United is expected to, once again, set a new MLS attendance record. They've sold more than 70,426 tickets for Sunday's game, the record they set earlier in the season while hosting Orlando.PHOTOS | ATLUTD