On Monday the Yankees announced that infielder and top prospect Gleyber Torres was seen by the team physician and diagnosed with a torn ulnar collateral ligament in his left elbow. 

As a result, Torres will undergo Tommy John surgery at a date to be determined and will miss the remainder of the 2017 season. Because Torres is not a pitcher and because the injury is to his non-throwing elbow, he's expected to be ready for spring training 2018. 

Torres entered the 2017 season as a consensus overall top-10 prospect. This season, he's batted .287/.383/.480 at the Double- and Triple-A levels with 23 extra-base hits in 55 games and good walk numbers. Those are impressive outputs for any minor-leaguer, let alone a 20-year-old like Torres who's playing against a much older peer group. 

The Yankees originally acquired Torres from the Cubs as the key part of the Arolidis Chapman trade of July 2016. New York of course subsequently re-signed Chapman to a free agent contract this past offseason. 

Long-term Torres has a ceiling as high as any prospect's in the game today. Near-term, the Yankees may have been poised to promote Torres and install him at third base in place of the struggling Chase Headley. Obviously, that will no longer come to pass.