Fans should have saved their excitement. In 117 plate appearances, Marrero whiffed 27 times and drew just 4 walks. He had 27 hits, but just 5 of them went for extra bases--all doubles.
Marrero's .248 / .274 / .294 line was good for a 53 wRC+--meaning that adjusting for park effects and run environment, Marrero was 53% as good as the average hitter, and that's including pitchers and premium fielders, which Marrero clearly is not.
Now, I don't mean to beat up on a 23-year-old getting his first cup of coffee. It's a small sample size. He's young enough that he still has time to get better.
But because of his pedigree as a heralded high-round pick, fans and media tend to vastly overrate his potential. And for a guy who talks a lot about meritocracy, GM Mike Rizzo gave Marrero a pretty much completely undeserved promotion.
In fact, Marrero might not even be the top first base prospect in the Nationals organization anymore. That's because while Marrero has been doing just barely enough to keep getting promoted, a late-round pick who lots of fans haven't even heard of has been earning every chance he's gotten. That guy is Tyler Moore.
Granted, Moore is about 18 months older than Marrero, and he was a level behind him each of the last two years. But still, Moore clubbed 62 homers in 2010-2011, while Marrero hit just 32. Even accounting for age differences, what Moore did this year in AA is more impressive than what Marrero did with AAA Syracuse. Plus, Moore isn't anyone's idea of a great fielder, but he's got a good arm and he's more agile than Marrero, which isn't saying a lot.
Scouts and stats guys alike doubt that Moore can overcome his lack of plate discipline to continue his success against the highest levels. This year, he struck out 139 times against just 30 walks in 546 plate appearances. If he can't improve his command of the strike zone, he'll have a hard time finding his way into hitters' counts and major league pitching will expose the holes in his swing. And while the homers are sexy, his .314 OBP means he's simply making too many outs.
Then again, a lot of people thought he'd get exposed in AA, and he handled that just fine thank you very much.
I don't think either Moore or Marrero is likely to ever be a productive major league starter. The right-right profile is tough to overcome, and the offensive standards are just so absurdly high at first base. If they want a championship caliber first baseman (Adam LaRoche ain't it), they're probably going to have to go after a free agent like Prince Fielder or Albert Pujols (why not?) or trade for someone like Kevin Youkilis.
But if these guys continue on their current paths in 2012, the next guy I'd like to see get a look in Nationals Park would be Tyler Moore, not Chris Marrero.