Which players' stone-cold starts should worry you?

— -- With almost the entire month of April in the books, playing-time totals are getting closer to the point where you can be legitimately excited or disappointed in a player's hot or cold start. Looking at the guys off to bad starts, who should you be genuinely worried about?

Position players

Jose Bautista, Toronto Blue Jays: The biggest April story on a team level has been the collapse of the Blue Jays, a repeat playoff participant. As the guy who's arguably their most visible player, Bautista has to own the team's start and has been a significant contributor to it.

There's good news and bad news here. The spike in his strikeout rate is scary, but he's actually hit his fly balls harder than the MLB average thus far, though admittedly not as hard as we're accustomed to seeing from him. He hasn't pulled the ball as regularly as in the past; on the ground, that's good, as it will help him beat a shift every now and then. But in the air that's a bad thing; selectively pulling for distance is an indispensable part of his arsenal.

On balance, I'm not overly worried. Bautista is clearly in decline, but I see the pulling deficit as a minor timing issue more than anything else. But if he's still whiffing 30 percent of the time at the end of May, all bets are off.

Curtis Granderson, New York Mets: With recent injuries to Yoenis Cespedes and perhaps Noah Syndergaard, things are drifting into worst-case-scenario territory for the Mets. While hitting these days seems to be all about hitting fly balls, there are inherent risks to such an approach at the plate. You lift and pull too much and you'll find yourself getting overshifted by defenses, and then your average collapses, and you had better hit for serious power.

Granderson found a comfy middle ground last season, cutting his popup rate to a career low while keeping his batting average out of the danger zone. This year, about a quarter of his fly balls have landed in infielders' gloves. That's a recipe for disaster. He's still a dead-puller on the ground, so there's no help there, and while his presently low line-drive rate should improve, it might not be enough to raise his average materially over .200. Even with his 20-homer power, that's a problem. I'd be worried.

Oh, and as an added bonus, Jose Reyes is cooked, in case you had any doubts. He's hitting tons of popups with no authority on any balls he puts into play. Paging David Wright, Amed Rosario, anyone...

Mark Trumbo, Baltimore Orioles: There is no margin for error for the all-or-nothing, high-strikeout, low-walk power hitter. Remember the "great" year Trumbo had in 2016? Even with all those homers (47), his wRC barely cracked 120 and he gave a bunch of his value back with his poor play in right field.

It's been more "nothing" than "all" so far; the strikeout and walk rates are right where they always are, and he simply hasn't been able to square the ball up into the air. His popup rate is way up as well, adding another layer of concern.

As with Bautista, I'm not too worried -- yet. Trumbo is extremely streaky, and he has been hitting his line drives as hard as ever. Minor timing adjustments should lead to a homer spurt before too long. Temper your expectations, however; 2016 was a best-case scenario for Trumbo offensively. At least he's DHing more this time around.

Dansby Swanson, Atlanta Braves: If you've read my work over at FanGraphs, you might know that I was not fooled by Swanson's gaudy 2016 numbers. They were inflated by an unrealistic .483 batting average on grounders, which he almost exclusively pulled -- inviting infield shifts.

He clearly hasn't been lucky this time around. His average fly ball velocity isn't all that bad, hovering just under 90 mph. That's a good thing when there's a bunch of 100-plus mph flies as part of that average. Unfortunately, a 90 mph fly ball is almost always an out, and Swanson hits a ton of them. Toss in his ongoing pull tendency on grounders plus poor strikeout and walk rates, and you've got a problem.

The diagnosis? Swanson isn't ready offensively and needs more minor league seasoning. He will grow into some power, but he needs to learn to use the entire field or it will be tough for him to bat .250.

Byron Buxton, Minnesota Twins: His underlying numbers are just as ugly as the ones on the back of his baseball card, so Buxton is officially a mess. He swings and misses constantly, and when he does make contact, it's often the worst types possible -- an infield fly, or a topped, soft ground ball. He showed flashes of juice in the second half of 2016, but he's given that progress back.

What can the Twins do? The Reds faced a similar situation with Billy Hamilton, and they have opted to reap the defensive benefits of playing him as he works through his offensive issues at the MLB level. The stakes are even higher with Buxton, who has way more upside with the bat but also a much lower floor. Forced to choose, I'd use up a minor league option and let the new front office take a crack at fixing him in a lower-pressure environment down on the farm.

Pitchers

Jeff Samardzija, San Francisco Giants: This one is easy: Samardzija's stratospheric ERA to date has been driven by a rate of line drives allowed over 30 percent. Even in a small sample, that almost never happens. He has always run up a strong strikeout rate, and this year it's been higher than ever. That could actually stick; liner rates are much more volatile than strikeout rates.

There's one more reason for optimism that's a little further under the radar. The grounders hit off of Samardzija have been struck very weakly thus far, but they have found more than their share of holes. His FIP has been running around three full runs better than his ERA; that sounds about right to me.

Tyler Anderson, Colorado Rockies: Those of you who have read my work at FanGraphs probably know how I feel about Anderson. He emerged as one of the game's premier contact managers last season, but his raw numbers so far tell a far different story this time around.

The good news is that Anderson continues to allow by far the weakest grounder contact numbers of any ERA-qualifying starting pitcher in either league. He has also been overly victimized by the mile-high air on his fly balls and liners allowed, as the actual damage allowed has been far greater than that suggested by the exit speeds yielded.

Anderson's rough start hasn't all been bad luck -- he needs to bring his fly-ball frequency back toward his 2016 levels. Even though everything looks bad now, his ceiling remains quite high.

Kevin Gausman, Baltimore Orioles: So much of what he's doing is exactly what you'd expect -- his fastball velocity, percentage of pitches in the zone, and contact rate are all similar to prior years. Gausman's strikeout and walk rates, however, have both moved sharply in the wrong direction thus far. What gives?

Well, hitters stopped chasing pitches out of the zone against him, making a key adjustment against a pitcher with a nasty but limited repertoire. Few pitchers throw as many four-seam fastballs as Gausman does, and he can settle into predictable patterns.

The slider has become Gausman's key pitch. It's the only thing resembling an off-speed pitch in his mix, and it has been hit hard over his career. As long as it isn't working, the whole is less than the sum of his parts.

Zach Davies, Milwaukee Brewers: The Brewers are scoring an awful lot of runs, which has helped obscure the early-season struggles of their most promising 2016 starter. Davies has always been a command guy, but the upward bump in his walk rate is worrying. His margin for error is slight, and he can't reduce it further.

That said, there's still a lot to like here. Ground balls hit against him are struck very weakly, thanks in large part to his effective changeup -- well under 80 mph on average in the early going. This hasn't translated to success, as hitters are hitting over .300 on the ground against him. That will come back down in Davies' favor. He has also fallen victim to some initial bad luck on fly balls. Assuming his command returns, he'll post a sub-4.00 ERA when all is said and done.

Robert Gsellman, New York Mets: Despite his high ERA, I submit that Gsellman remains a bright spot for the Mets. You can't easily teach a guy to generate such a high rate of ground balls, and his average launch angle is actually below zero in the early going.

Gsellman's poor early-season results have been driven by a rate of line drives allowed, which is highly likely to come back down. Hitters have wrought maximum damage on those liners, hitting over .800 and slugging almost 1.300, way worse than his exit speeds allowed would suggest. He was a great insurance policy for the Mets' rotation last year, and will be again in 2017.