Drew, 31, is batting .176/.255/.328 in 39 games for the Sox this season. His start to 2014 was delayed because he didn't sign until May 20 -- a consequence of his having draft pick compensation attached to his free agency (Drew turned down a qualifying offer from the Red Sox this past offseason).
In 2013, Drew was a core contributor to the Sox's championship team, as he batted .253/.333/.433 and played outstanding defense at shortstop. Across parts of nine big-league seasons, Drew owns an OPS+ of 97. Drew is eligible for free agency again this coming offseason.
Johnson, 32, is batting .219/.304/.373 this season and owns a line of .251/.333/.424 across nine major-league campaigns.
This marks the first time that the Yankees and Red Sox have pulled off a trade with each other since the August 1997 deal involving Mike Stanley, Tony Armas Jr. and others.