Prior to 2015, the highest level Philadelphia Phillies outfielder Odubel Herrera had ever achieved was 197 games for the Texas Rangers' Double-A affiliate in 2013 and '14. In those 197 games he did pretty well, batting .288/.330/.370 with 28 doubles, 11 triples and four home runs. 

Last season, in 96 games at Double-A, it jumped up a notch, with a slash line of .321/.373/.402 with 16 doubles, four triples, two homers, 47 runs scored, 48 RBI, all at just 22 years old.

It was those numbers that caught the eyes of Phils brass in the offseason when Texas made Herrera available in the Rule 5 draft. For those who don't know, teams are forced to leave a certain number of players in their minor league system open to being drafted in the Rule 5 draft, with the stipulation that any team that selects a player from another team must keep that player on their active roster for the entire season. 

In other words, if you take a player from another team in the Rule 5 draft, there is no sending him down to the minors. He's on your 25-man roster the whole season. If not, he is offered back to his original team.

This is why most Rule 5 picks don't ever amount to much. Sure, there have been exceptions, among them Josh Hamilton, Johan Santana, Dan Uggla, Shane Victorino, Joakim Soria, Jose Bautista. But those cases are the exceptions. The norm is for teams to select a player and then send him back to his original team before the team even breaks camp in the spring.

But with the Phillies in the midst of a rebuilding year, there was plenty of room on their 25-man roster for a player who had an interesting hit tool, if not a specific position. Now, with less than a month to go in the regular season, Herrera has been more than anyone could have hoped for, batting .302, with a .340 on-base percentage, a slugging percentage of .434 for an OPS of .774 and an OPS+ of 111. His eight home runs are more than he's put together in any minor league season and is currently the only .300 hitter on the Phils. 

His second-half stats are even more eye-popping, slashing .356/.407/.491 with a weighted on base average (wOBA) of .391 and a weighted runs created (wRC+) of 149. That'll do.

Herrera won't enter into any of the NL Rookie of the Year conversation, but he will certainly get a stray vote here and there. Among all National League rookies who qualify for the batting title, his 3.0 fWAR is tied for fourth, his .302 batting average is third, his 57 runs scored is fourth, his 14 stolen bases are second, and his 26 doubles are tops among all NL rookies.

And while he had never played the position on a regular basis, Herrera has been the team's starting center fielder for pretty much the entire season and done quite well, according to Fangraphs' defensive metrics. He has six defensive runs saved this year, seventh-best in all of baseball, and an ultimate zone rating (UZR) of 4.3 (meaning he's saved about 4.3 runs so far this year). That's ninth-best. He's no Kevin Kiermaier, but for a 23-year-old getting his first licks in as an every day center fielder, Herrera has acquainted himself quite nicely.

As the Phils continue their rebuild, it appears they've hit on something solid with Herrera. Sure, he has a high batting average on balls in play (.383), but so does every other rookie near the top of the leaderboards. His walk rate could be better (just 4.6% of his plate appearances end in walks), but for now, it's an acceptable shortcoming.

Herrera has certainly locked down one of the team's three outfield spots for 2016 and may become another name to add to the list of relevant Rule 5 picks before too long.