Aviles was hitting .222 with five home runs and 31 RBI in 53 games prior to the transaction, so the Royals will not immediately miss him or his struggles.
In return, the Royals are gaining two young players with upside—one a utility player with some pop and speed on the base paths and the other a relief pitcher who is averaging 9.8 strikeouts per nine innings in the minors this season.
Navarro has played in the major leagues since 2010 and has not performed particularly well. His career batting average is only .177 in 79 at-bats—however that is not to say he will not break out later on. In the minor leagues, he has hit as many as 11 home runs and stolen as many as 18 bases in a season.
Though it seems the Royals “won” this trade, they are losing a bit by dealing Aviles. Though he has not shown it this year, Aviles has the ability to hit for a respectable average (he batted .304 last year). He also knows when to pick pitches to steal on—he is 10-for-12 in stolen base attempts this season and 33-for-43 in his career.
Aviles is something of a modern day Bill Buckner, in that his season averages are up and down consistently every other year. In odd-number years from 1971 to 1980, Bill Buckner never hit above .284. In even-number years, he never hit below .301. Aviles has never hit below .304 in even-number years, though in odd-number years his average hardly scratches the Mendoza Line.
At the moment, the Royals got the best of this deal. However, that may change in the future if Aviles maintains his pattern and hits over .300 next year—and especially if the two youngsters the Royals received do not pan out.