It's reached the point in the 2021 MLB season that every game -- let alone series -- involving a postseason contender can have a profound impact on that club's playoff hopes.

That said, certain series each week carry slightly more weight than others. Here's a look at the five series this week that figure to have the most influence on the postseason picture.

• Complete up-to-date standings

Blue Jays at Rays (Monday-Wednesday)

Why it matters
The Blue Jays entered the week holding on to the second NL Wild Card spot, but it remains a tight race. The Rays, meanwhile, are getting closer to locking up home-field advantage in the AL, but their recent slide -- Tampa Bay is 8-9 in September, including 4-7 in its last 11 games -- has opened the door for the Astros.

Other teams that will be watching closely

Red Sox, Yankees, A's, Mariners, Astros
Boston is just one game ahead of Toronto for the first Wild Card spot -- and, in turn, home-field advantage in a potential AL Wild Card Game. That matchup is far from set in stone, though, with the Yankees (1 1/2 games back), A's (two games) and Mariners (four games) still within striking distance.

How to watch
Tuesday's game will be televised nationally on ESPN, while the entire series can be seen live on MLB.TV.

Cardinals at Brewers (Monday-Thursday)

Why it matters
The Cardinals have started to open up some separation in the race for the final NL Wild Card spot, but as they've proven over the past couple weeks, that can all change quickly -- especially with this four-game set against the first-place Brewers looming. As for Milwaukee, the Crew is likely going to finish as the No. 2 seed in the NL, though there is still an outside chance the Brewers can chase down the Giants and Dodgers for the top record in the Majors.

Other teams that will be watching closely

Phillies, Reds, Padres
The Phillies' easiest path to the postseason is now catching the Braves in the NL East, but they're still in the Wild Card hunt. The Reds and Padres, meanwhile, have stumbled in the standings in recent weeks after holding that final Wild Card spot at various times over the past month. Cincinnati enters the week just 3-7 in its last 10 games and San Diego is 2-8 in its last 10 -- all while St. Louis has rattled off nine wins in its last 10.

How to watch
The first three games can be seen live on MLB.TV, while Thursday's game will be broadcast exclusively on YouTube.

Yankees at Red Sox (Friday-Sunday)

Why it matters
The Yankees looked poised to make the postseason after reeling off 13 straight wins last month, but they're now on the outside looking in for the two AL Wild Card spots. They entered the week 1 1/2 games back of the Blue Jays for that final spot and 2 1/2 back of the Red Sox, who hold the top AL Wild Card spot.

Other teams that will be watching closely

Blue Jays, A's, Mariners
The good news for these three clubs is that either the Yankees or Red Sox will have to lose each night. Of course, the bad news is one of them also has to win. Either way, the Blue Jays entered the week in control of their own path to the postseason, while the door will be open for the A's and Mariners to make up ground on at least one of those clubs.

How to watch
All three games can be seen on MLB.TV, while Friday's opener and Sunday's finale will also air on ESPN. Saturday's contest can be seen on MLB Network.

Braves at Padres (Friday-Sunday)

Why it matters
The Braves are clinging to the NL East lead in their quest to win a fourth straight division title, while the Padres are desperately trying to escape their second-half freefall and stay in the NL Wild Card race.

Other teams that will be watching closely

Phillies, Cardinals, Reds
The Phillies are nipping at the Braves' heels in the NL East -- and the two rivals meet for a three-game set in Atlanta during the final week of the regular season. This week will go a long way toward determining the significance of that showdown, as the Phillies play host to a pair of last-place teams in the Orioles and Pirates, while the Braves head west to face the D-backs and Padres. As for the Cards and Reds, St. Louis is trying to hold off both Cincinnati and San Diego for the final NL Wild Card spot.

How to watch
Saturday's game will air on FOX, while all three games in this series can be seen on MLB.TV.

Phillies at Pirates (Thursday-Sunday)

Why it matters
The Phillies' second-half rollercoaster continues. Every time it looks as if they've faded out of the postseason race, they go on a run to get right back in it. Now, they have a golden opportunity to continue making up ground this week when they play seven games against the Orioles and Pirates.

Other teams that will be watching closely

Braves, Cardinals, Reds, Padres
As mentioned, Atlanta is trying to hold off Philadelphia in the NL East. While winning the division is likely the Phillies' best bet to make the postseason at this point, they are also still in the Wild Card mix with the Cards, Reds and Padres.

How to watch
This entire four-game set can be seen live on MLB.TV.