Small sample size can be a fantasy owner's worst enemy. Too often, we jump to conclusions, either positive or negative, based on very little data.
That's kind of where we're at, just a week into the Minor League season. Some guys are off to ridiculously hot starts -- no, Blue Jays catching prospect Danny Jansen will not hit .545 this year. Others are really struggling -- no, Fernando Tatis Jr. will not hit .154 this year. So our best advice right now is to take a deep breath and not go jumping after prospects, or cutting bait on them, based on one week.
With that in mind, not a ton of changes to report in this week's top 10. A couple of new names, with a desire to get some arms into the mix, and a little tweaking of the order.
1. Ronald Acuna Jr., OF, Braves (Previous rank: 1)
Yes, the 20-year-old phenom is off to a slow start (3-for-25 with 10 strikeouts), but remember that he started this year's Grapefruit League season 1-for-11 and then went on to hit .432 (19-for-44) with four homers and a 1.247 OPS. We all know it's a matter of when, not if, he gets his first shot in Atlanta.

2. Nick Senzel, 3B, Reds (Previous rank: 5)
The injury to Eugenio Suarez in Cincinnati has everyone wondering if Senzel will get the chance to show what he can do. The advanced bat will play in the big leagues and it is interesting to note that after playing his first four games at second base defensively, a move made because of Suarez's emergence at the hot corner, Senzel moved back to third for his past two games.
3. Willie Calhoun, OF, Rangers (Previous rank: 2)
Injuries are hurting the Rangers' big league roster and the current options in left field aren't setting the world on fire. There is little doubt on our end that Calhoun's power will play in a Major League lineup and could help a Texas team that hasn't been scoring a ton of runs.
4. Gleyber Torres, INF, Yankees (Previous rank: 3)
As a prospect fan, I'd like to see both Torres and Miguel Andujar in the Yankees' infield. In reality, not sure that will happen any time real soon. But Torres is going to show he's ready for the big leagues soon (8-for-24 start is encouraging) and his offensive upside is considerable.
5. Jack Flaherty, RHP, Cardinals (Previous rank: Unranked)
Flaherty got an early start with St. Louis, striking out nine over five innings. It wasn't enough for him to stick around (he was only filling in for Adam Wainwright), so he went down to Triple-A and promptly struck out 11 in seven innings. He has 20 K's and just one walk in 12 innings for those scoring at home. Think Miles Mikolas is looking over his shoulder?

6. Victor Robles, OF, Nationals (Previous rank: 4)
Everyone held their breath when Robles left his Triple-A game with an arm injury after attempting a diving catch. It's a hyperextended elbow and we'll know more next week. That obviously could impact his standing on a list like this, but we'll be optimistic and leave him on given his enormous tools.
7. Dustin Fowler, OF, Athletics (Previous rank: 7)
Fowler competed for the center-field job all spring, but it's not a bad thing he's getting ABs in Triple-A after that horrific knee injury suffered with the Yankees last June. His power-speed combination should be ready for Oakland soon enough and those currently getting any time in center (Boog Powell, Jake Smolinski and Trayce Thompson) are a combined 6-for-46.

8. Austin Hays, OF, Orioles (Previous rank: 6)
This is one of the slow starters you shouldn't worry too much about. Hays was dinged up early in Spring Training, so he's just getting his feet under him now. He has homered twice and it's fair to expect many more to come as he hits his way from Double- to Triple-A and into Baltimore's outfield plans.
9. Francisco Mejia, C, Indians (Previous rank: 9)
There might not be anyone who thinks Mejia isn't ready to hit big league pitching. The main question is how to get that bat into the lineup. He has played two games in left field, one game at third and three behind the plate in the early going in Triple-A. Mejia won't supplant either big league backstop, and the Indians wouldn't want him to be a backup anyway, so showing he can at least hold his own at numerous positions might be his ticket for now.

10. Michael Kopech, RHP, White Sox (Previous rank: Unranked)
Any of a number of pitchers who had strong debuts could crack the list, but none has the upside and potential to impact your fantasy roster like Kopech. He struck out eight in four innings in his first outing of 2018 and the White Sox's big league pitching staff sits last in the American League in ERA.
Dropped out:Christian Arroyo, 3B, Rays (Previous rank: 8); Eloy Jimenez, OF, White Sox (Previous rank: 10)