Many teams tried to upgrade their 25-man rosters for potential playoff runs by making deals before last week's non-waiver Trade Deadline. But that's not the only way they can try to improve between now and the end of the regular season.
Many teams in contention have the chance to promote from within should the need arise. A year ago, hitting prospects Andrew Benintendi and Willson Contreras made huge impacts late in the year. So did young pitchers Alex Reyes and Julio Urias.
Some of the top 10 potential contributors have been up in the big leagues already, while some are awaiting their first taste of the highest level. All are on the recently re-ranked Top 100 prospects list, with their current rank in parentheses.
1. Walker Buehler, RHP, Dodgers (13)
Buehler has now made four appearances since his promotion to Triple-A. Don't let the bad numbers overall there fool you, as the right-hander was very good in two starts after getting roughed up in his debut at the level. His last outing came in relief, perhaps a harbinger as his stuff could play well out of the Dodgers' bullpen down the stretch.
2. Brent Honeywell, RHP, Rays (14)
Like Buehler, Honeywell's long-term future is as a starter, and after an up-and-down outing in Triple-A, he's posted a 1.71 ERA and a 1.10 WHIP with a K/BB ratio better than five-to-one in four starts since the All-Star break. Anyone who saw him dominate for two innings in the SiriusXM All-Star Futures Game, earning MVP honors, knows he could provide a boost in relief if the Rays need him.

3. Lewis Brinson, OF, Brewers (15)
The toolsy outfielder has been up and down a couple of times this season already without really getting to show what he can do in his 47 big league at-bats. But Brinson's .335/.405/.548 line with double digits in home runs and stolen bases at Triple-A are more indicative of what he brings to the table, even with the friendly home ballpark in Colorado Springs.
4. Francisco Mejia, C, Indians (16)
This might be a reach given that Mejia hasn't played above Double-A, but he can flat out rake (.315/.367/.521). He also has a strong arm behind the plate, one that's thrown out 33 percent of would-be basestealers this season.
5. Willy Adames, SS, Rays (18)
Adames has more than held his own at age 21 in Triple-A, hitting at or near the top of Durham's lineup all season. The Rays' big league middle infield hasn't exactly set the world on fire offensively, and he could be an upgrade. Adames has seen a little time at second base this year, though he's primarily a shortstop.
6. Alex Verdugo, OF, Dodgers (28)
Cody Bellinger is already up; is there room for Verdugo, too? Even after scuffling a bit after the All-Star break, the outfielder is hitting .316/.387/.430 and can play all three outfield positions. There may not be room, especially if Bellinger gets pushed back to the outfield, but Verdugo could be an interesting bat off the bench when rosters expand in September.
7. Chance Sisco, C, Orioles (50)
The O's have gotten decent production from their big league tandem of Welington Castillo and Caleb Joseph, so maybe Sisco is more of a September callup type. Having a third catcher on the bench, one who can hit and get on base (.314/.392/.426 in Minor League career), could come in handy.

8. Jack Flaherty, RHP, Cardinals (53)
The National League Central race is tight and the Cardinals recently gave Luke Weaver a start to give veteran Adam Wainwright some extra rest. Should there be another need, Flaherty is one of the hottest starters in the Minors, with a 1.52 ERA, a .190 batting average against and a 9.1 K/9 rate in five second-half starts in Triple-A.
9. Chance Adams, RHP, Yankees (61)
The Yankees are chasing the Red Sox in the American League East and lead the Wild Card race. Recent trades have certainly firmed up the big league rotation, but Adams has earned a chance should they need reinforcements with a combined 1.99 ERA and a .177 batting average against across two levels in 2017.
10. Ryan McMahon, 1B/2B/3B, Rockies (64)
After a rough 2016 campaign, McMahon has hit his way from Double-A to Triple-A, with a combined .356/.402/.589 line, 18 homers and even 11 steals. There isn't one spot in Colorado's lineup that needs an upgrade, but McMahon has enhanced his potential value by showing an ability to play three positions and could be a fantastic left-handed-hitting option off the bench.