The 2018 non-waiver trade deadline is 4 p.m. ET on Tuesday, July 31, meaning it is less than 24 hours away. Already several big name players have been traded, including Manny Machado and Zach Britton, though you can be sure more deals will go down between now and the deadline. Make sure you don't miss anything with our trade tracker. You can also follow the latest news and rumors on CBS Sports HQ.

With the trade deadline inching closer and closer, here is a primer on the biggest storylines to watch before the clock strikes 4 p.m. ET on Tuesday.

Archer may actually be on the move

MLB: Detroit Tigers at Tampa Bay Rays
Chris Archer trade chatter seems more serious than ever. USATSI

Reports indicate the Rays are more open to trading Chris Archer now than ever before, and that's understandable. His performance has slipped and the clock is ticking on his sweetheart contract. In all likelihood Archer's value will only go down from here. The 2018 trade deadline might be Tampa Bay's last best chance to trade him for a monster package.

Archer is certainly no stranger to trade rumors -- he's been mentioned as a trade candidate for years now -- though that doesn't make it any easier. Here's what Archer told Marc Topkin of the Tampa Bay Times over the weekend:

"That's the strangest part,'' Archer said before Sunday's 11-5 loss, their third straight to the majors-worst Orioles. "That's why this situation is unsettling, because everything else is pretty much in our control.

"I've got the baseball in my hand. And now my career is not in my hands. That's fine, that's the business part of it. But that's why it's unsettling.''

The Padres, Dodgers, Braves and Yankees have all been connected to Archer in recent weeks and I reckon several other teams have interest as well. He is under team control through 2021 at very team-friendly terms, which is why even a rebuilding team like San Diego is in the mix. 

It seems Archer is very available, the this might be the year the Rays finally take the plunge and say yes to a trade.

Will the Nats actually sell or even consider trading Harper?

The Nationals should sell. Absolutely. This past weekend the Nationals had a chance to show everyone, most notably GM Mike Rizzo, they can make a second half run and get back into the postseason race. Instead, they split four games with the Marlins, and scored one run total in the final two games of the series. Washington is 52-53 and six games out of a postseason spot.

If the Nationals do sell, it would more likely be a quick retool rather than a rebuild. Impending free agents like Gio Gonzalez, Kelvin Herrera and Ryan Madson are most likely to go. Would the Nationals trade Bryce Harper, another impending free agent? It's probably not likely, but it's looking increasingly possible:

As for specifics, the Indians may be a potential Harper destination: 

Point is, the Nationals flopped over the weekend and now it's up to Rizzo to actually move forward with a trade deadline sell off, and put the team in the best position to win in 2019.

Surprise NL East contenders looking to load up

While the Nationals fade out of the race, the upstart Phillies and Braves have taken control of the top of the NL East. The two clubs have made the transition from rebuilder to contender this year, and both are reportedly seeking upgrades at the deadline. The Braves have added Brad Brach and are looking for a controllable starting pitcher, and possibly a third baseman as well. On Monday night, they added outfielder Adam Duvall, who figures to play a platoon role in Atlanta. 

The Phillies, meanwhile, have added Asdrubal Cabrera, and it sound as though they had a deal in place for Adam Jones before Jones invoked his no-trade clause to remain with the Orioles.

Philadelphia comes into the week 1 1/2 games up on the Braves in the NL East and the two teams have seven head-to-head games remaining this season. Furthermore, all seven will be played within the final two weeks of the season, including the final three games of the year at Citizens Bank Park. The NL East race could go down to Game 162 and both the Braves and Phillies want to use the deadline to put themselves in the best position to win the division.

Bullpen musical chairs

As always, relievers are a hot commodity at the trade deadline. In addition to Britton and Brach, we've also seen Brad Hand, Jeurys Familia, Ryan Pressly, Joakim Soria, Seung-Hwan Oh and others trades in recent days. On Monday, Seattle added Zach Duke and Adam Warren to the fold. Here is a not at all complete list of bullpen arms who could be traded before the deadline:

The Red Sox, Dodgers, Braves and Astros are among the contenders looking for bullpen help at the deadline. Some relievers, like the Marlins trio, are under team control long-term and could interest rebuilding teams as well as contenders. Lots of relievers have been traded already and I would bet on lots more relievers being traded before the deadline.

Do the Brewers have more moves coming?

It has already been an active trade deadline for the Brewers. They added Soria to beef up the bullpen and Mike Moustakas to fix their second base problem -- incumbent third baseman Travis Shaw has slid over to second in deference to Moustakas -- though there is still a clear need for another starting pitcher. 

Here is Milwaukee's current rotation depth chart:

  1. Chase Anderson
  2. Jimmy Nelson (rehabbing from shoulder surgery)
  3. Zach Davies (out with a back injury and recently suffered a setback)
  4. Jhoulys Chacin
  5. Brent Suter (out with Tommy John surgery)
  6. Junior Guerra
  7. Wade Miley
  8. Freddy Peralta

Not great! Not terrible, but not great either. There is definitely room for improvement. GM David Stearns has already acted to address his bullpen and infield. It stands to reason he will act to improve the rotation before the deadline, either with a rental stopgap (Matt Harvey?) or a pitcher under long-term control (Chris Archer?).

The Twins could be active

MLB: Minnesota Twins at Toronto Blue Jays
The Twins have already traded several players and Dozier could be next. USATSI

Already the Twins have traded Pressly (to the Astros), Eduardo Escobar (to the Diamondbacks), Duke to the Mariners, and Lance Lynn (to the Yankees). They might not be done either. Minnesota is 48-56 and nine games out of a postseason spot and their list of impending free agents is loaded with useful players:

That list does not include Joe Mauer, who is an impending free agent and very unlikely to be traded considering he is Mr. Minnesota and has a full no-trade clause. It's more likely Mauer will sign an extension (at a greatly reduced salary) than be traded.

Anyway, even if you're down on Morrison and Rodney and don't believe they have much trade value, Dozier could be useful to a contender down the stretch (though his market continues to shrink now that Boston has dealt for Ian Kinsler). Santana too, and he's not necessarily a rental. Kyle Gibson is in the middle of a long awaited breakout season and he's been mentioned in trade rumors, though he will remain under team control through 2019, so the Twins don't have to move him.

Now that the Twins have taken the plunge and traded Escobar (an impending free agent) and Pressly (not an impending free agent), it feels like only a matter of time until they start moving other players.

Don't forget, trades can still be made in August

Did you favorite team miss out on the help they need before the deadline? Don't worry, trades can still be made in August. They're just slightly more complicated because players have to go through trade waivers. Here's how that process works. Justin Verlander was traded via trade waivers last August It's possible to get not only good players in August, but great players.

To me, the best August trade candidate is Blue Jays third baseman Josh Donaldson. He has not played since May 28 due to a calf injury, though he is working out at the team's spring training complex in Florida and is expected back on the field sometime soon. Once Donaldson plays a few games to show teams he's healthy, I imagine the Blue Jays will shop him around to see whether they can deal him for something more valuable than the draft pick they'd receive if he leaves as a free agent this winter.

Other potential August trade candidates include Dozier and Santana with the Twins, Giants outfielder Andrew McCutchen, Tigers righty Jordan Zimmermann, and Nationals infielder Daniel Murphy. Pretty much any injured or underperforming veteran making big money is an August trade candidate. It's easy to forget now, but Verlander had a 4.29 ERA at the trade deadline last year. Sometimes being thrown into a postseason race can re-energize an underperforming veteran.