The New York Mets were bouyed by the performance of several key rookies in what was an otherwise disastrous season, and outfielder A.J. Ewing was definitely one of them. Ewing was a defensive star and a lineup spark plug initially, but he slumped badly in the middle of the season before he was able to make a nice rebound.
That did leave questions about whether his success is sustainable, though, and Max Ralp h of MLB.com took a run at those. He started by reviewing Ewing's season, so let's begin there.
Ewing rose quickly through the upper levels of the minors at the end of last year, and his .961 OPS in 30 games between Double-A and Triple-A helped him make it to Citi Field on May 12 despite the fact that he's just 21 years old.
That ended up not mattering initially. Ewing walked three times, tripled, stole a base and drove in two runs, and he was the first player with that stat line in a debut since at least 1900. His only out was a 102.3 mph flyout to the warning track, per Ralph.
He stayed hot for some time after that, and Ewing even succeeded as the Mets leadoff hitter for a time. He also played elite defense, and it looked like Ewing was going to join fellow rookie outfielder Carson Benge in taking the league by storm.
Not so much in August, however. Ewing posted a brutal slash line of just .171/.243/.219 for the month, but turned that around in September, posting a season-high .861 OPS and four homers in 23 games.
The big question going foward is Ewing's chase rate, which is tied into the other question Ralph posed about his offensive ceiling. His overall chase rate was 26.7 percent, but it increased noticeably in August, although Ralph didn't provide that stat breakdown.
He compensates to some extent with what the writer called a "solid" walk rate of 9.3 percent. And Ewing is a constant threat on the base paths with his ability to steal, although he was still thrown out too much as he was learning the league.
As good as Ewing was, there's room for improvement. There's some power to be tapped there, but the risk is that the outfielder becomes pull-happy. Hopefully that doesn't happen, because the tools are all there for Ewing to continue to become a star.

