Things can change quickly when it comes to prospects.
In just the past week, the top name on last week's "Next in Line" list—infielder Xander Bogaerts of the Boston Red Sox—was promoted and has made his major league debut. The same goes for Travis d'Arnaud, a top young catcher with the New York Mets, who was included in the honorable mentions category.
You'll have to find out where those two rank now that they've graduated to the "Already Up" section of our weekly look at a batch of prospects who could make a fantasy impact from here on out in 2013.
Bogaerts and d'Arnaud, though, are far from the only prospects you'll want to keep an eye on between now and season's end.
But before we get to that, here's a reminder of the criteria for this column:
This spot will include prospects who already have been called up ("Already Up"), as well as others who are in the minors but are considered to be major league-ready and on the verge of getting the call ("Next in Line").
To allow for more turnover from week to week, the list below does not include young players who have exhausted their prospect eligibility by exceeding 130 at-bats or 50 innings pitched.
1. Christian Yelich, 1B/OF, Marlins (33.2 Percent Owned)
Yelich didn't have a great week (3-for-22, albeit with a solid 4:4 K:BB), but he stays atop the rankings because he's a top-notch prospect who's playing everyday and doing enough (.269 BA, 16 R, 2 SB) to keep that spot. This is at least until next week, when he may no longer retain his prospect status due to surpassing 130 at-bats.
2. Xander Bogaerts, SS/3B, Red Sox (14.7 Percent Owned)
Bogaerts would be No. 1 if the 20-year-old phenom had gotten off to a smashing start—he's only played in two games and is still searching for his first big league hit since being promoted—or if it looked like he'd be playing more regularly. For now, the righty-hitter will likely play shortstop over starter Stephen Drew against lefties, while also seeing some fill-in time behind Will Middlebrooks at third base.
3. Khris Davis, OF, Brewers (23.8 Percent Owned)
The 25-year-old Davis doesn't get much pub in the prospect world, but he's been red-hot while the rebuilding Brewers have been giving him a chance to show what he can do—which is hit .324 (23-for-71) with six homers and 13 RBI. Since August started, he's been even hotter: .378 BA, 4 HR, 9 RBI.
4. Danny Salazar, RHP, Indians (8.5 Percent Owned)
Salazar, 23, has now made four starts for Cleveland and has struck out more than a batter per inning in each of them. Through his first 23 frames, he's got 29 whiffs (against only seven walks), while allowing just nine earned runs on 15 hits.
5. Sonny Gray, RHP, Athletics (40.8 Percent Owned)
This 2011 first-rounder's stuff isn't quite as electric as Salazar's upper-90s heat, but Gray is hanging with him, start after start. In his first three outings, the 23-year-old has gone 21 frames, while giving up only four earned on 10 hits and six walks to go along with 21 strikeouts. Pitching half the time at the cozy Coliseum will only help, too.
6. Jarred Cosart, RHP, Astros (4.9 Percent Owned)
This will likely be Cosart's final time here, as he's up to 45 innings over his initial seven outings. And what an initiation into the majors it's been for the 23-year-old, who owns a 1.60 ERA and 1.18 WHIP, despite a subpar 21:21 K:BB ratio. Of course, that .231 BABIP and 85.3 LOB percentage won't last.
7. Kolten Wong, 2B, Cardinals (3.7 Percent Owned)
The 22-year-old Hawaiian native just missed the cut after being promoted last week, because his role was in question given St. Louis' lineup. But it's clear that the Cards are doing what they can to get his lefty bat into the mix by shifting regular second baseman Matt Carpenter to third and resting David Freese against righties. That makes it easier to recommend a guy who hit .303 with 10 homers and 20 steals at Triple-A, and one who already has three steals in seven big league games.
8. Scooter Gennett, 2B, Brewers (13.2 Percent Owned)
If you're in need of some help at second base, you've got some options, right? Gennett isn't quite the prospect that Wong is, but he's getting everyday PT and has triple-slashed .404/.451/.681 since the start of August. Sometimes, opportunity is just as important as talent, especially this late in the game.
9. Corey Dickerson, OF, Rockies (2.4 Percent Owned)
Dickerson, 24, is still playing pretty regularly while Carlos Gonzalez remains sidelined, and he's continued to be productive in spurts. Overall, he's batting .298 with two homers, eight RBI and 15 runs scored. He's notched at least one hit in 13 of 18 August games.
10. Wilmer Flores, 3B/SS, Mets (2.6 Percent Owned)
The 22-year-old Flores, who had career-highs in average (.327), doubles (36) and RBI (86) at Triple-A, has held his own as the injured David Wright's hot corner fill-in. In his first 46 at-bats, Flores has 12 hits (.261 BA) to go with three doubles, a homer and 11 RBI.
Honorable Mentions: Travis d'Arnaud, C, Mets; Andre Rienzo, RHP, White Sox; Brett Oberholtzer, LHP, Astros; Jonathan Villar, SS, Astros; Chia-Jen Lo, RHP, Astros
Players who have exhausted their prospect eligibility since last week: Alex Wood, Braves; Junior Lake, SS/OF, Cubs; Taylor Jordan, RHP, Nationals
Next in Line
1. George Springer, OF, Astros (0.1 Percent Owned)
Now that Bogaerts is up, Springer takes the top spot here, despite the news that he's going to remain at Triple-A through the rest of the minor league season and the playoffs. Sure, he may not come up until mid-September, but the 23-year-old is approaching a 40-40 season in the minors, for pete's sake. He is too explosive to ignore.
2. Nick Castellanos, 3B/OF, Tigers (0.0 Percent Owned)
The 21-year-old has cooled off since his .361/.441/.583 June, but he has arguably the clearest path to playing time among elite, near MLB-ready hitter prospects because of Detroit's blah left-field duo of Andy Dirks (.661 OPS for season) and Matt Tuiasosopo (.509 OPS in second half).
3. Billy Hamilton, SS/OF, Reds (0.6 Percent Owned)
His .312 OBP in his first shot at Triple-A proves that Hamilton, 22, has more work to do to make himself into an all-around big leaguer. But for fantasy purposes, all owners should care about is that he gets a chance to show off the wheels that helped him to a minor-league-record 155 steals a year ago, as well as another 72 this season.
4. Taijuan Walker, RHP, Mariners (0.1 Percent Owned)
After a five-start mini-slump—he surrendered 20 earned runs and 45 baserunners over 27.1 frames—the 21-year-old hurled five scoreless with six whiffs Tuesday. If the M's want to give Walker some action in Seattle, they should do so soon, since he's at a career-high 135.1 innings after the 126.2 he pitched a year ago.
5. Erik Johnson, RHP, White Sox (0.0 Percent Owned)
This 2011 second-rounder has been dynamite while splitting 2013 between Double-A and Triple-A, as his 2.01 ERA, 0.97 WHIP and 8.2 K/9 prove. Similar to Walker, though, Johnson is likely nearing a shutdown, as his eight scoreless innings Monday brought him to exactly 130 on the year—about 40 more than his previous career-high.
Honorable Mentions: Archie Bradley, RHP, Diamondbacks; Kevin Gausman, RHP, Orioles; Marcus Stroman, RHP, Blue Jays; Mike Olt, 3B, Cubs; Rafael Montero, RHP, Mets
All ownership percentages courtesy of ESPN Fantasy Baseball.