A majority of the Divisional titles have been decided in the MLB, but which each side will play which has yet to be determined and the final games of the regular season will sort out who meets who in the postseason.
MLB announced that the playoffs were to be extended from this season with 12 teams having the opportunity to reach the postseason by increasing the Wild Card spots to three in each league.
The New York Mets face the Washington Nationals in a three-game series at Citi Field. The Mets have relinquished the lead in the National League East Division to the Atlanta Braves, having lost the series 3-0 between the two sides at Truist Park in Atlanta.
The Braves have been hot on the heels of New York in the second half of the season - at the start of June Atlanta were 10 and half games behind the Mets, but have chased and chased and gradually caught them up and overtaken them.
The Braves are now favourites for the NL East title, which would be their fifth divisional championship in a row, as they travel to Miami to take on the Marlins.
Atlanta require just one win over the Marlins in their final series this week, or if the Mets lose a game in their series then the defending World Series champions will win the Division.
Should the Braves and Mets finish with identical records, then Atlanta will win the Division, having taken the season series over the Mets 10-9.
The Mets arrived in Atlanta over the weekend knowing they needed just one win to keep the title in their own hands, so getting swept wasn’t on the agenda.
There is still plenty to be decided over the next three days, however the Mets won't be in a good place mentally knowing they were so close to securing their first divisional title since 2015 and now all they can do is pray for help.
Speaking to the official Mets website, team manager Buck Showalter said: "We'll see if we can still make it happen, but, we're going to need some help now, that’s what's frustrating."
The National League Wild Card picture became clearer leading into this week as the San Diego Padres clinched their spot in the playoffs thanks to the Milwaukee Brewers' loss in extra innings to the Marlins at American Family Field.
With that defeat Milwaukee's hopes of making it to the playoffs are hanging by a thread because the Philadelphia Phillies beat the Nationals in Washington, lowering the Phillies' magic number down to one.
The Padres lead the Phillies in the Wild Card seedings by one game for the second berth and the Phillies lead the Brewers by two games for the third Wild Card spot.
The Seattle Mariners lead the Tampa Bay Rays by one and a half games for the second Wild Card spot, with both sides having clinched a spot in the postseason.
The Rays are on a poor run of form currently losing seven of their last 11 games.
With their loss to the Houston Astros on Sunday and the Toronto Blue Jays’ win over the Boston Red Sox, the Rays won't be hosting a Wild Card series as they will miss out on the fourth seeding in the American League.
Sunday's sequence of events means that the Rays won't face the Mariners in the opening round, so Tampa will start their postseason facing either the Blue Jays or the Cleveland Guardians.
Speaking following the defeat to the Astros, team manager Kevin Cash spoke to the official Rays' website and said: "A lot of things would have had to go in our favour. We'd like to play in front of our fans. Now, we're going to have to do a little bit more to get that opportunity."
The earliest the Rays can play in front of their own fans would be game three of the Division series against either the Yankees or the Astros, providing they can advance through the Wild Card series.