His competition is Tony Pena, Jr....he BETTER stick.
KC would be better served trying to boost their offense than their defense, so they can probably spare the mediocre glove work. He's had a good start in the 12 games he has under his belt this year, but a troubling stat I'm just noticing is only 2 BB in 47 PA. He's a pretty good contact hitter, though. But in the end, he was called up out of desperation to help the Royals' offense, since just about any SS on any AAA team could out-hit Tony Pena, Jr.
And regarding job security, if the Royals do wind up trading Grudzielanak, Aviles would most likely take his spot for the rest of the season barring a huge slump.