It's a Deadline day redux.
Last month's non-waiver Trade Deadline had a lot of intriguing action, and perhaps we'll see another slew of swaps in the leadup to midnight ET tonight, which is the deadline for clubs to add players who will be eligible for their postseason rosters. August waiver activity isn't always sexy, but once in a generation or two, you get something like the Astros' acquisition of Justin Verlander just before the stroke of midnight last year. Nothing similarly stratospheric appears to be on tap this year, but let's hope that doesn't stop execs from trying to make their squads a little more, well, august.
Here are five other hot topics heading into the weekend in MLB:

1. The West is yet to come
One month, three teams. That's what we've got left in the National League West. And perhaps this will be a good weekend for the Rockies, who will be playing the last-place Padres while the D-backs and Dodgers continue to duke it out at Dodger Stadium. The four-game series between Arizona and Los Angeles began Thursday night with a 3-1 D-backs win and continues tonight with Hyun-Jin Ryu opposing Zack Greinke (10:10 p.m. ET), Saturday with a southpaw showdown between Clayton Kershaw and Patrick Corbin (9:10 p.m.) and Sunday with rookie Walker Buehler taking on veteran Clay Buchholz (4:10 p.m.).
In addition to their battles with the Dodgers and Rox, the D-backs still have six games left against the NL Central-leading Cubs and the American League-West leading Astros. Theirs is probably the toughest remaining schedule in baseball.
The Dodgers, meanwhile, have the NL's best run differential, and it could be only a matter of time before that differential is more properly reflected in their record.
With those factors taken into account, you can understand why the Dodgers -- despite being in third place and two games back of the D-backs -- are still projected to win this race in the statistical models provided by sites like FanGraphs and Baseball Prospectus. But the models might be meaningless with so many direct tussles still on the season schedule. Counting this weekend's action in Los Angeles, each of these three remaining West contenders has at least two series remaining against each of the other two clubs.
That's why, if you're ranking the races, the NL West is the best, and it's really heating up this weekend.

2. Mission: M-possible?
Time's running out for the Mariners. They've made an effort to shape this roster into something postseason-presentable, to overcome that 80-game suspension of Robinson Cano and the decline of Felix Hernandez and the recent absence of staff ace James Paxton and end the longest active postseason drought in North American professional sports. But Seattle has given up more runs than it has scored, and the club has seen the bloom come off the rose that was its early-season dominance in one-run tilts and watched what was an eight-game advantage in the AL Wild Card race as recently as July 3 get blown up like so many Fourth of July fireworks. The Mariners will finish with sub-.500 records in both July and August.
So you can't overstate the importance of the four games that Seattle is playing in Oakland this weekend. The Mariners' only chance of overcoming all of the above is to take care of business head-on. They did that Thursday night with a 7-1 victory that pulled them within 4 1/2 games of the A's for the second Wild Card spot. In the continuation of a four-game set, it's a meeting of Mikes tonight (Mike Leake vs. Mike Fiers at 10:05 p.m.), then the eagerly awaited return of Paxton opposite Daniel Mengden (Saturday, 9:05 p.m.) and, finally, King Felix, coming off his best start in months, squaring off against Edwin Jackson (Sunday, 4:05 p.m.). The odds are stacked against the M's, but the A's rotation is pretty banged up.

3. Get your Phil
The Phillies got into this beautiful mess that is the NL potseason picture ahead of schedule. Before they started making a slew of moves for veteran pieces like Wilson Ramos and Jose Bautista, they had the lowest average roster age in the sport, and they had entered the season with little expected of them.
Within that context, what's happened these past few weeks -- losses in 14 of 22 games -- isn't terribly alarming. But the context has shifted as 2018 has evolved. Philly was in first place from July 6 to Aug. 12. The loaded Nationals fell out of the running, leaving it up to these Phils and the budding Braves to figure out what happens in a suddenly uprooted East. Atlanta has been the one rising to the new challenge in this home stretch, and the Phillies find themselves trying to avoid a finish not quite as demoralizing as the infamous "Phold of '64" but upsetting nevertheless.
Here's the challenge ahead this weekend: A bolstered Cubs club now featuring 100 percent more Daniel Murphy and boasting the NL's best record. It's Nick Pivetta opposite Jose Quintana in tonight's 7:05 p.m. opener at Citizens Bank Park. The Phillies moved NL Cy Young Award candidate Aaron Nola up a day to Sunday's finale to get him an extra start at home -- opposite Jonathan Lester. The Phils won't be seeing their old friend (and the recently rejuvenated) Cole Hamels. But they will see a chance to prove their late-season mettle, and on the heels of a Bautista-aided comeback win Wednesday, perhaps pick up some steam both in the East and the incredibly complex NL Wild Card picture.

4. Viva velo
There is beauty in the slop-throwing soft-tosser who colors the corners, outthinks his opponents and makes the most of his reduced repertoire. That is a form of baseball art.
But we still like the dudes who throw the you-know-what out of the baseball, too.
Tonight's 8:10 p.m. tilt at Guaranteed Rate Field between the Red Sox and White Sox presents a couple of those dudes opposing each other.
Nathan Eovaldi's average four-seam velocity, per Statcast™, is 97.0 mph. Among starters with at least 1,000 pitches thrown this season, only Noah Syndergaard (97.7) and Luis Severino (97.6) throw harder (and Eovaldi has been working with Hall of Famer Pedro Martinez to correct his mechanics). It's a much smaller sample for White Sox starter Michael Kopech, who has thrown all of eight innings in the bigs so far and has "only" averaged 95.9 with his heater. But this is the prospect who has been known to run it all the way up to 105 mph.
Boston and the South Siders are Sox on very different feet right now -- one skipping toward October, one mired in the rebuild mud. But pitching matchups like this bring the heat.

5. Battle for the basement
Bobby Witt Jr. is the son of 16-year Major League veteran pitcher Bobby Witt. He is a stud shortstop at Colleyville (Texas) Heritage High School, a five-tool talent, and if the way-too-early 2019 mocks are to be believed, the favorite to be taken with the No. 1 overall pick in next June's MLB Draft.
Perhaps somebody ought to get young Witt a seat for this weekend's Orioles-Royals affair at Kauffman Stadium, which begins at 8:15 p.m. ET tonight, because there's a not-small chance he winds up playing for one of those squads.
In spite of some respectable (and ultimately regrettable) efforts to improve their rosters in advance of the 2018 season -- let the record show these were not "tank" jobs aimed at earning the No. 1 pick -- these two clubs have had an abysmal year. They're both on pace for fewer than 53 wins -- a mark only nine teams have been unable to reach in a non-strike season in the 162-game era.
So this is an unusually compelling matchup of fifth-place squads. The O's are 2 1/2 games behind the Royals, which means Baltimore is actually 2 1/2 games "ahead" of Kansas City. What's on the line? Witt's on the line!