SB Nation's Minor League Ball has gone back and did a review of their preseason top 50 rankings.
They had LHP Mike Montgomery as the 16th best prospect before the season:
16) Mike Montgomery, LHP, Royals: 2.61 ERA with 88/31 K/BB in 93 innings on the season, including four starts in High-A, 13 in Double-A, and three rookie ball rehab starts. Remains a strong prospect, just needs to stay healthy.
Montgomery is usually one of the names tossed in there when talking about the future of the Royals minor league system. Staying healthy, though, is a concern, especially for a young pitcher.