April is dirty air. Is a player just in a slump that we wouldn't spend five seconds discussing if it happened in July? What's a trend and what's small-sample-size fluke? What's a slow start and what's a real regression in skill? Bad weather, running into a couple of hot pitchers, a few lines drives hit right at 'em -- it doesn't take much to send fans into a state of panic.

Albert Pujols is hitting .232/.284/.333. He's homerless through 17 games and 69 at-bats. He has fewer RBIs than Chad Tracy, who has started one game all season.

Pujols is supposed to be feared, the baddest dude on the planet, The Machine, built to punish baseballs. Pitchers aren't afraid of him right now. He has fewer walks than Kirk Nieuwenhuis, Michael Brantley, Mark DeRosa or George Kottaras, who is Milwaukee's catcher. Backup catcher.

(Are you worried about Pujols' slump? Vote here at SportsNation.)

Yes, it's April. It doesn't take much to turn around that triple-slash line. If Pujols goes 3-for-4 with two home runs and a walk Wednesday night he'll be hitting .260/.316/.438. If he goes 2-for-4 with a home run and a double the next night he'll be hitting .273/.333/.494. If he goes 3-for-5 the game after that he'll be hitting .293/.348/.500.

Still, 17 games, no home runs. Maybe it's not fair, but $240 million machines aren't allowed to go into extended slumps.

Of course, Pujols isn't a machine. He's human and he's now 32 years old. In 2008, he posted a career-high 1.114 OPS. Since then, his batting averages have fallen from .357 to .327 to .312 to .299. His on-base percentage has dropped from .462 to .443 to .414 to .366. His slugging percentage declined from .653 to .541 last season.

That's a strong trend -- three consecutive seasons in which he wasn't quite as good as the year before, with 2011 in particular being a noticeable decline. Was he still a terrific hitter? Yes, he ranked 10th in the NL in OPS, 11th in wOBA. But the Angels didn't sign him to be the eighth or 10th or 11th best hitter in the league. They signed him to be the best, even at 32. And Pujols still hit 37 home runs last season, and that was despite missing 15 games with a fractured forearm. So you factor in that injury, a slow start to the season (.245 in April, two home runs in May), a career-low .277 average on balls in play and maybe it was just one of those seasons.

Pujols has gone through homerless stretches of this length before. He even had a 105-at-bat stretch last season. He had a 79-at-bat stretch in 2009 and stretches of 77 and 75 at-bats in 2007. So while 69 at-bats is a lot without a home run, it's not unprecedented. Teammate Torii Hunter said it's just a matter of Pujols adjusting to a new league. "For Albert, this is totally different," Hunter said. "He doesn’t know any of the pitchers. I’m his scouting report. But when he figures it out, there’s going to be trouble. This guy is good, man."

Maybe it's that simple. Learn the pitchers. Stop pressing. Heck, according to FanGraphs, Pujols' line-drive percentage right now is 25 percent, well above his career mark of 19.1 percent. So throw in some bad luck, as well.

Except there are signs that we'll never again see that .330, 40-homer, best-player-in-baseball Pujols.

Most problematic: Pujols' decreasing walk rate. Check out his unintentional walk rates since 2008:

2008: One walk every 7.5 at-bats

2009: One walk every 8.0 at-bats

2010: One walk every 9.0 at-bats

2011: One walk every 12.6 at-bats

2012: One walk every 23 at-bats

How does this manifest itself? Check out the heat map below. On the left is Pujols' chase percentage versus sliders and curveballs in 2011; on the right, his chase percentage versus sliders and curveballs in 2012.

Albert Pujols has been chasing sliders and curveballs outside the strike zone so far in 2012 (right). ESPN Stats & information

Now, this can be construed a couple of ways. We have our small sample size. Or we have a classic example of an older player trying to speed up his bat against fastballs and getting fooled by off-speed stuff. After hitting .301 against sliders and curves in 2011 (10th best in the majors), Pujols is hitting .091 against those pitches in 2012, a problem created by a chase percentage on sliders and curves outside the strike zone of 58 percent -- a figure exceeded only by Clint Barmes, Chone Figgins, Dee Gordon and Chris Davis. Not exactly a group of hitters you want to be associated with.

This is a continuation of a trend over the past few seasons. As Sam Miller pointed out the other day on Baseball Prospectus, Pujols is simply swinging more:

2009: 40 percent

2010: 41 percent

2011, first half: 41 percent

2011, second half: 49 percent

2012: 47 percent

In 2009 and 2010, Pujols chased just 24 percent of pitches out of the strike zone. That increased to 30 percent in 2011 and 34 percent so far in 2012 -- above the overall average of 28 percent.

Look, it's just 17 games, but those 17 games have reinforced the image of a hitter who is no longer the Albert Pujols whom opponents fear. Maybe it's a slump, maybe it's something with his eyes and, yes, maybe he's just pressing.

Maybe. Or maybe he'll never be the best hitter in baseball again. The Angels signed Pujols for 10 years. I wouldn't worry about 2021. I'd worry about how dominant Pujols will be in 2012.

(Thanks to William Cohen and Jeremy Lundblad of ESPN Stats & Information for research help.)

Follow David Schoenfield at Twitter @dschoenfield.