With only five weeks left in the Major League season, every series featuring a postseason contender is obviously important -- but some carry a bit more weight than others.

Here's a look at five series this week that could have significant implications on various postseason races.

RED SOX at RAYS (Monday-Thursday)

Why it matters
There was a time not too long ago that this matchup may have seemed like it could be for AL East supremacy. Instead, the Red Sox begin the week trying to hold onto the final AL Wild Card spot -- or possibly catch the Yankees for the first AL Wild Card berth. Of course, a four-game sweep by Boston could tighten things up significantly in the division, but Tampa Bay begins this series sitting eight games up on Boston.

Other teams that will be watching closely

Astros, Athletics, Blue Jays, Mariners, White Sox, Yankees
Any AL team with postseason aspirations will have some interest in this series. The A's, Blue Jays and Mariners are trying to catch the Red Sox for the final AL Wild Card spot. The Yankees are trying to either catch the Rays for the AL East title or at least hold off the Red Sox to secure home-field advantage in a potential AL Wild Card Game. Even the White Sox and Astros are still hoping to close the gap on the Rays for the top record -- and home-field advantage in the AL.

Players to watch
J.D. Martinez broke out of an 0-for-20 slump with a three-hit game on Saturday, including what proved to be the game-winning three-run homer in the 10th inning. Chris Sale is also expected to take the mound on Wednesday as he continues his comeback from Tommy John surgery.

As for the Rays, rookie Wander Franco began the week having reached base safely in 29 consecutive games. Meanwhile, Joey Wendle is coming off a massive two-homer, six-RBI game on Sunday.

How to watch
Monday's series opener can be seen on ESPN while Thursday's finale will be televised on MLB Network. The entire set can be seen live on MLB.TV.

BREWERS at GIANTS (Monday-Thursday)

Why it matters
The Brewers have opened up a comfortable lead in the NL Central, but the Giants begin the week just 2 1/2 games ahead of the Dodgers. Aside from their respective division races, Milwaukee comes into this series just 5 1/2 games back of San Francisco for the NL's best record.

Other teams that will be watching closely

Dodgers, Reds
The Dodgers are nipping at the Giants' heels in the West, while if the Reds are going to make any type of run in the NL Central, they'll need the Brewers to stumble against the first-place Giants.

Players to watch
It will be worth keeping an eye on Kris Bryant, who exited Friday's game against the Braves due to right side tightness. The Giants are hopeful that Bryant will be able to return for this series against the Brewers, possibly as soon as Monday's opener.

How to watch
The first three games of the series can be seen live on MLB.TV, while Tuesday's game will also be aired on FS1. Thursday's game will be available exclusively on YouTube.

BRAVES at DODGERS (Monday-Wednesday)

Why it matters
The Braves have started to pull away a bit in the NL East, but they have a tough matchup to start the week against the Dodgers -- a team with plenty to play for in its own right. Los Angeles is closing in on San Francisco not just for the NL West crown, but also the best record in MLB as a whole.

Other teams that will be watching closely

Giants, Mets, Phillies
The Giants begin the week with just a 2 1/2-game edge on the Dodgers for the top record in the Majors. As for the Mets and Phillies, they each open the week with series against the Marlins and Nationals, respectively -- the two NL East bottomfeeders -- while the Braves will have their hands full with the Dodgers. If there's any chance for New York or Philadelphia to make a run down the stretch, it could start here.

Players to watch
Reigning NL MVP Freddie Freeman is once again putting up MVP-caliber numbers in 2021, but the Braves' other corner infielder may actually have an even more compelling MVP case this time around. Austin Riley enters this series hitting .303 with a .914 OPS and a team-leading 28 homers -- including 14 since the All-Star break (41 games).

We'll see if Riley can keep it going this week against a pair of NL Cy Young Award candidates in Walker Buehler (Tuesday) and Max Scherzer (Wednesday). The Dodgers, meanwhile, have an MVP candidate of their own in Max Muncy, who has 28 homers and a .924 OPS.

How to watch
Monday's series opener will air on ESPN and Wednesday's finale will be on MLB Network, while the entire series can be seen live on MLB.TV.

ATHLETICS at BLUE JAYS (Friday-Sunday)

Why it matters
The A's have fallen completely out of the AL postseason picture with their recent slide, while the Blue Jays have been battling just to stay in the mix. Both clubs began the week on the outside looking in, but the winner of this series would certainly get a bit of a boost in the AL Wild Card race.

Other teams that will be watching closely

Mariners, Red Sox, Yankees
The A's are the first team on the outside looking in at the Yankees and Red Sox, who hold the two AL Wild Card spots. Boston began the week 2 1/2 games clear of Oakland, while Seattle (4 1/2 games back) was next in line and Toronto (5 1/2) was also still hanging around.

Players to watch
If not for Shohei Ohtani, this series would feature a battle of potential AL MVPs in Matt Olson and Vladimir Guerrero Jr. Olson entered the week with 32 homers and a .925 OPS, while Guerrero has 36 home runs and a .994 OPS.

How to watch
The entire series can be seen live on MLB.TV.

DODGERS at GIANTS (Friday-Sunday)

Why it matters
This will be the final regular-season meeting between the Dodgers and Giants, as the NL West archrivals continue to battle for the NL West crown -- and the best record in Major League Baseball.

Other teams that will be watching closely

Brewers
There is still an outside chance that the Brewers could catch these two clubs in the race for home-field advantage, but this series is clearly more so just about the two teams involved.

Players to watch
Buster Posey, the 2012 ML MVP Award winner, is having an incredible year for the Giants, hitting .312 with 15 homers and a .926 OPS. This series will feature two other former MVPs in Kris Bryant (2016 NL MVP with the Cubs) and Mookie Betts (2018 AL MVP with the Red Sox). Clayton Kershaw, the 2014 NL MVP, remains on the injured list.

How to watch
The first two games of the series will air on MLB Network, while Sunday's series finale will be featured on ESPN. The entire series can be seen live on MLB.TV.