Top 50 prospects update

At the MLB season's midpoint, just before the signing deadline for drafted players, here is a fresh look at the top 50 prospects still in the minor leagues, including a new name on top.

These rankings are based primarily on upside or ceiling, not on proximity to the majors, so the list includes a mixture of players as high as Double-A or Triple-A and a few who have signed but have yet to make their professional debuts.

Drafted players who haven't signed are ineligible, as is anyone currently on a major league roster. I've also omitted several pitchers who have missed significant time this year with arm injuries, waiting until they return to rerank them as needed.

1. Jurickson Profar, SS, Texas Rangers (age 19)
Current level: Double-A (Frisco)

Preseason ranking: 7

Profar has the ultimate mark of an elite prospect. He keeps improving even as he is challenged with better competition. In this case, the Rangers jumped the 19-year-old two levels to Double-A, where he has continued to hit for average, get on base, make contact, show surprising power for his size, hit from both sides of the plate and play plus defense. There's no real hole in his game, and he looks as if he'll be more than ready for the majors before he turns 21 -- another mark of a potential superstar -- if the Rangers can create a spot for him.