Baseball America has released their mid-season Top 50 Prospect List, and the only Ranger prospect who makes the top 50 is third baseman Mike Olt, who checks in at #44. You can see my writeup and scouting report on him from this winter here.
Players in the majors as of July 1 were not considered, so Jurickson Profar and Martin Perez were not eligible for consideration on this list.
Olt was #43 on the BA top 100 list heading into the 2012 season, and was #22 before this season, but his struggles earlier this season, stemming from vision issues, appear to have resulted in him dropping in the rankings.
Joey Gallo is listed as part of a group of 10 players who missed the cut, but who BA said were worthy of notice.
This season has been a mixed bag for Rangers' top prospects...Cody Buckel is in extended spring after losing the ability to throw strikes, Jorge Alfaro has a broken hand, and Lewis Brinson and Joey Gallo have had nice seasons in low-A, but not big-time breakout years. I have a hard time disagreeing with BA's assessment that only one Ranger prospect deserves to be in the top 50 right now.