10 Fantasy Baseball Players to Buy and Sell for Week 17

Ian Desmond is going to have a hard time sustaining his power numbers, making him an ideal sell-high candidate. Here are nine other players to buy, sell or hold in season-long formats.

In season-long fantasy baseball, the art of wheeling and dealing, especially at this time of year, when injuries can ravage a fantasy roster and hot and cold streaks seem rampant, is especially important.

Knowing when to buy low and who to sell at their highest value is tricky business. No one wants to sell a player they think is going to crater only to see that player provide a lot of fantasy production all season long, and no one wants to buy a player on a hot streak only to see him crash down to earth.

Every week, we take a look at 10 players that you should either be buying shares in or selling. This week's list features a red-hot Cardinal, a couple of the game's best closers (when healthy), and a player I had told you to sell a few months ago who nevertheless keeps on performing.

Buy Matt Carpenter

There is not hotter a player in baseball than St. Louis Cardinals first baseman/third baseman Matt Carpenter.

From the beginning of the season through May 15th, Carpenter hit .140/.286/.272 with 3 homers and 13 RBIs, with a wRC+ of 59 (140 plate appearances). Pretty awful. Since May 16 (259 plate appearances) however, he's hit .347/.440/.752 with 22 bombs, 40 RBIs and 53 runs scored, with a wRC+ of 213. That's some turnaround!

On Friday, Carpenter hit three home runs and two doubles in six innings -- 16 total bases -- in a blowout win over the Chicago Cubs. He'd be tough to land in a trade right now, but he's worth trying to buy-high on.

Buy Zach Britton

When Zach Britton ruptured his Achilles during a workout last offseason, everyone knew it would take some time before he was himself again. Well, the Baltimore Orioles' closer is back now and is at the center of a number of trade rumors. It's likely the Baltimore left-hander is going to end up with a contender at some point in the next few days, and that could mean many more save opportunities for Britton owners.

So far this year, the numbers haven't quite been there for him. In 16 appearances (15.2 innings), he has a 3.45 ERA and 4.43 FIP, with a strikeout rate of 20.6% and a very high walk rate of 15.9%. Those numbers are unsustainable to be a good late-inning relief pitcher, and his fastball velocity has been lacking this season, averaging 94.4 miles per hour, down from 96.1 miles per hour a season ago. However, that velocity has crept up in recent outings, averaging 95.4 miles per hour or higher in each of his last six appearances.

If he lands with the Houston Astros -- one of the teams reportedly after him -- and becomes their closer, he turns into a potential fantasy goldmine for some lucky owner.

Buy Vince Velasquez

Don't look now, but Philadelphia Phillies starter Vincent Velasquez may be starting to figure out this whole starting pitching thing. He was dominant in his last outing on Sunday against the lowly San Diego Padres, going seven innings and giving up no runs on two hits with one walk and seven strikeouts. He's sporting a 4.09 ERA on the season, but with a FIP of 3.67 and an xFIP of 3.77. He's striking out 10.39 batters per nine with a strikeout rate of 27.9%, up from 21.6% a season ago.

In his last six starts, he's been even better, posting a 2.38 ERA and keeping some pretty good company along the way.

He'll still have some outings where he gets shelled, but Velasquez, more often than not, has been a good starting pitcher this year and he piles up strikeouts.

Sell Ian Desmond

Colorado Rockies first baseman/outfielder Ian Desmond has 19 home runs this year. That's good! Desmond also has a batting average of .238. That's bad.

Desmond has knocked in 58 runs this year. That's good! Desmond has an on-base percentage of just .309. That's bad.

Desmond has an isolated power of .230. That's good! Desmond has a wRC+ of 92. That's bad.

There's also this.

If you have him on your roster, sell Ian Desmond before the homers dry up, because no one who hits the ball on the ground this much can sustain this type of dinger pace, even if they play half their games in Coors.

Sell Cody Allen

The Cleveland Indians' bullpen has been a disaster this year, a far cry from the lights-out brigade that helped them storm their way to the World Series two years ago. One of the biggest problems has been closer Cody Allen, who has 20 saves but an ERA of 4.95 and FIP of 4.88. His strikeout rate has fallen from 32.6% in 2017 to 28.8% this season, and his walk rate has jumped from 7.5% to 10.0%.

Now, the Indians have added San Diego Padres All-Star closer Brad Hand to the relief corps. So far, Allen remains in the closer role, but it wouldn't be a surprise if, at some point soon, Hand becomes the ninth-inning guy for the Tribe, thereby erasing any value Cody Allen has.

Buy Zack Greinke

OK, I'm done telling people to sell Zack Greinke. The Arizona Diamondbacks' ace continues to get the job done, despite a decrease in fastball velocity for the last two seasons. On Sunday against the Chicago White Sox, he twirled eight innings of one-run ball, and struck out 13 while walking one and giving up just one hit.

He's proven his bounce-back season last year was no fluke, with an 11-5 record and an ERA of 3.05 with a 3.40 FIP in 2018. His strikeout rate is almost exactly what it was last year -- 26.2% compared to 26.8% in '17 -- with a walk rate that has fallen from 5.6% to 4.6%.

No matter what your stuff looks like, getting hitters to bat a meager .230 against you (it was .228 last season) proves you've still got the goods.

Sell Mike Moustakas

The Kansas City Royals appear ready to trade third baseman Mike Moustakas to a contender in the next couple weeks, and you should feel free to do the same in your fantasy leagues.

Moustakas did hit 38 homers last year and does have another 19 so far this season. He can hit the ball out of the yard, but he doesn't bring much else to the table. His slash line of .245/.308/.457 isn't terribly impressive, and perhaps more to the point, he's been awful over the last two months of the season.

In June, Moustakas had an OPS of .665, and here in July, it's .623. These are not the kind of numbers you want to see from your fantasy third baseman.

Buy Corey Dickerson

In baseball today, there are a lot of complaints that there are too many three-outcome hitters in baseball -- players who mostly walk, strike out or hit home runs. But if you're looking for a baseball player who is the exact opposite of that, then you're probably a fan of Pittsburgh Pirates outfielder Corey Dickerson.

Dickerson is batting .315/.347/.509 in 360 plate appearances this season, with 11 bombs, 42 RBIs and 47 runs scored. He has a wRC+ of 128 and wOBA of .363, both of which are career highs. However, he's doing it with a walk rate of just 3.9%, the lowest of his career. He also has an extremely low strikeout rate of 12.5%, half of what it was last season (24.2%).

It's hard to tell if this is sustainable or not. The good news is he doesn't hit the ball on the ground a ton, with a 36.1% ground-ball rate, 37.8% fly-ball rate and a line-drive rate of 26.0%. He's also impervious to shifting, spraying the ball all around the field, with a pull rate of 32.3%, opposite-field rate of 30.3% and up-the-middle rate of 37.4%. That allows him to get more ground-ball singles and find more holes.

He's also homered in four straight games and is hitting .391 in July, so perhaps now is a good time to just hold on to him -- or try to trade for him.

Hold Dallas Keuchel

It's hard to know what to make out of Dallas Keuchel, frankly. He won the Cy Young Award in 2015 with a 2.48 ERA and was worth 5.9 fWAR. The next year, he had a 4.55 ERA and was worth 2.7 fWAR. Last year, he did better, with a 2.90 ERA but only 2.5 fWAR. And so far this year, he has a 3.60 ERA but is already worth 2.3 fWAR.

There is one pretty common theme among Keuchel's numbers, however, are his FIPs -- 2.91, 3.87, 3.79 and 3.66 -- over the last four seasons. His strikeout rates have fallen during the last four years -- 23.7%, 20.5%, 21.4% and a career-low 17.8% this season. He's also walking fewer hitters, though, with a 6.2% walk rate, down from 8.1% last year.

Let's see how his first few starts in the second half play out before making a call on Keuchel, who can be very effective or very hittable, depending on the season.

Buy Trevor Story

Trevor Story continues to mash, with a .293/.357/.552 slash line, 20 homers, 68 RBIs, 51 runs scored and 13 stolen bases. Everything here checks out, too.

He's one of the best offensive shortstops in the game, and much of that is due to his reduction in strikeouts, with his strikeout rate down to a career-low of 25.4%. Last year, he whiffed 34.4% of the time, and it was 31.3% in his rookie season.

There are only two shortstops in baseball with a better wOBA than Story's .384 -- Manny Machado (.400) and Francisco Lindor (.394).

I'm buying Trevor Story now.