Everyone knows spring training statistics largely don't matter. Many veteran hitters are working on swing changes or focusing on changing their approach. Veteran pitchers are trying out new pitches or dedicating more time to getting the ones they don't throw that often to be a little better.

And frankly, some veterans just don't care what happens in the land of palm trees and desert sand.

So when a pitcher gets lit up in a spring start or heads north with an ERA a full run or two higher than their career average, it's generally not a cause for concern. But there are things that happen in the spring that do matter.

And right up at the top of the list is when a pitcher suddenly loses their fastball velocity. That's why there is a level of concern over Arizona Diamondbacks starter Zack Greinke.

The Arizona Republic is reporting that, through his first two spring outings, Greinke has yet to crack 90 mph on his fastball (topping out at 89.5 mph), according to StatCast data. He was knocked around pretty good by Mexico's World Baseball Classic lineup, allowing 6 hits in 2.2 innings.

Last year, Greinke hit 93 mph in his second spring start, so this is definitely a concern for a franchise that was already worried about their $200-plus million investment. However, the hurler says he's not too concerned. Yet.

“It’s still early,” Greinke said. “It is what it is. It’s still early and it’s not like some crazy, crazy thing. But it’s not ideal, either.”

After two straight All-Star seasons in 2014 and 2015 and coming off a year in which he finished runner-up in the NL Cy Young race, Greinke struggled in his first year in the desert. He produced a 4.12 ERA, which was a huge jump from the 3.04 ERA he'd averaged since 2007 and the 2.86 ERA he had in the previous two seasons combined.

Last year, Greinke averaged 91.3 mph on his fastball, which was a career low, slower than his 91.8 mph in '15, and well below the 94.0 mph he registered while still with the Kansas City Royals as a 23-year-old.

Compared to his career numbers, his 2016 performance was down across the board.

Losing 0.5 mph is one thing, but if the spring radar guns are to be believed, Greinke is throwing about 2 mph slower than he did last year, and that could be a cause for concern, especially after he missed his final couple of starts last September because of a sore shoulder.

The D-Backs were likely a little spooked by his subpar 2016 season as it was, especially after the shoulder soreness crept up. Now, there is the drop in velocity. These are not good signs for a pitcher now in his mid-30s that has thrown a total of 2,253.1 innings in his career.

As for your fantasy baseball drafts, this news should definitely raise alarm bells. According to FantasyPros, Greinke's average ADP is 89th overall, which equates to being the 21st starting pitcher being taken off the board. That means he's getting taken somewhere in 7th round in 12-team leagues. In our recent 14-team numberFire mock draft, Greinke was taken at the end of the 7th round at 97th overall, the 33rd starter selected.

And in our fantasy projections for 2017, we project a 3.69 ERA and a 1.24 WHIP for Greinke in 183 innings pitched. He is ranked as the 31st best pitcher according to our nF metric, giving him a score of 3.09.

The wisest course would be to shy away from Greinke for now, at least until he gets a few more spring training starts under his belt. If his velocity returns, then his current projections are a good baseline. However, his case sounds an awful lot like what happened to former Philadelphia Phillies ace Roy Halladay, who lost his fastball in the spring of 2012 and never recovered.

Drafting those types of guys usually leads to bad things.