The signing: The Colorado Rockies have agreed with outfielder Gerardo Parra on a three-year, $27.5 million contract. That contract could be a bargain -- or the expected rate for a competent third/fourth outfielder. The trouble is Parra is one of the more difficult players in the sport to evaluate. Even in 2015, he hit .328/.369/.517 in 100 games for the Brewers, well above his career norms; after being traded to the Orioles, he hit .237/.268/.357 in 55 games, a playoff-race acquisition who hurt more than he helped. Check out his season-by-season WAR totals:

2011: 3.0

2012: 1.9

2013: 6.1

2014: -0.3

2015: 1.0

So what happened in 2013? Baseball-Reference.com uses defensive runs saved from Baseball Info Solutions, which credited Parra with one of the greatest defensive seasons ever recorded, with 41 DRS. While he did win his second Gold Glove that season, it appears to be an anomaly. This is his year-by-year DRS total in the outfield (he's played all three positions):

2011: +14

2012: +8

2013: +41

2014: -1

2015: -10

I don't think it's possible for a fielder to lose 51 runs of value in two seasons unless he played 2015 on a broken leg. That said, his raw range factors are down; that doesn't factor in the tendencies of the pitching staff, balls in play and so on, and his rating in 2013 included 17 baserunner kills. The metrics do suggest he's slowing down, however, and I'm inclined to agree with that. It will be interesting to see how he fares defensively in Colorado, where there's a lot of ground to cover. Anyway, the Rockies aren't really getting a 6-WAR player, but they hope they aren't getting the guy who struggled in Baltimore.

The reason: Well ... you got me. The Rockies already have Carlos Gonzalez, Charlie Blackmon and Corey Dickerson as their starting outfielders, and they all hit left-handed, like Parra. Brandon Barnes is the right-handed backup, but his park-adjusted OPS+ of 68 was ninth-worst among 128 outfielders with at least 200 plate appearances, so you'd think the Rockies would have been more interested in a right-handed bat.

On the other hand, when's the last time Gonzalez, Blackmon and Dickerson were all healthy at the same time? Dickerson played just 65 games last season, Gonzalez just 70 the year before. So maybe signing Parra is just a necessary way of upgrading their fourth outfielder, who will probably get a lot of playing time.

The impact: The speculation will be that this signing is a prelude to a Gonzalez trade. Gonzalez belted 40 home runs last year, but he's owed $37 million the next two seasons. The free-agent market for Justin Upton and Yoenis Cespedes has been slow, but that can be read two ways regarding a possible Gonzalez trade: (A) If those two are having problems finding a home, it's going to be difficult to trade Gonzalez and (B) Gonzalez at two years and $37 million is perhaps more attractive than Upton or Cespedes at $100 million, even if it means giving up some prospects to get him.

Look, it doesn't really make sense for the Rockies to keep him. Given the rosters of the Dodgers, Giants and Diamondbacks, the Rockies aren't going to win the division. They aren't going to compete for a wild card. Gonzalez has rebuilt his trade value after 2014 and a slow start in 2015. Gonzalez still makes sense for the Angels, who need a left-handed bat but have little left on the farm to get him. The White Sox have been interested in Upton or Cespedes on shorter-term deals, so Gonzalez works there. Maybe there will be interest from the Cardinals or Blue Jays, who just traded Ben Revere and are currently relying on the injury-prone Michael Saunders in left.

The Rockies can also wait until spring training to see who gets injured, or who's left without Upton or Cespedes, or wait until the trade deadline. Either way, I suspect Gonzalez won't be wearing a Rockies uniform on Aug. 1.

For more on the Rockies, check out the Rockies Zingers blog.