10 Fantasy Baseball Players to Buy and Sell for Week 18

With Week 17 in the books and the playoffs on the horizon, it is officially decision-making time regarding your fantasy baseball team.

Maybe your squad has been plagued by injuries, and it is time to cut bait on guys you would have preferred to hold on to because you're in win-now mode. Maybe you have a comfortable lead in the standings and can afford to take a chance on some buy-low players in hopes of a bounce back heading into the later stages of the season.

Regardless of where your team sits right now, you should always be looking to take advantage of market inefficiencies on players.

Perhaps a slow start is just a product of bad luck and a small sample size. Maybe the reason you're in first place is due to the stellar but possibly unsustainable play of some players you can sell high on. If you're not sure whether you should hold or fold on a player, don't sweat it. That's why we're here.

The following 10 players have seen a perceived change in their fantasy stock, and we'll attempt to decipher which warrant taking action.

Hold Yu Darvish

Yu Darvish is in the midst of his worst season as a pro, with a 4.01 ERA and what would be a career-low 9.72 strikeouts per nine innings (K/9). While his 3.82 xFIP suggests there should be some positive regression, what really is important for Darvish is his move away from Globe Life Park in Arlington.

Darvish has maintained a horrific 5.38 ERA at home this season, as opposed to a sparkling 2.49 ERA on the road. That shouldn't come as much of a surprise, considering his home park ranks as the fifth-most hitter friendly this season, according to park factor. He'll make the move to Dodger Stadium, which ranks 16th in park factor.

In addition to pitching in a more friendly environment, Darvish should benefit from the move away from the more hitter-friendly American League. He also will be playing for the team with the best record in baseball and the fifth-most runs scored per game, which doesn't hurt.

All you're going to get for Darvish at this point is buy-low offers, so be sure to hold onto him to see how he fares in a different environment.

Buy Nelson Cruz

Nelson Cruz's power is a bit down this season, and his wOBA would be his lowest since 2013. However, he currently has a hard-hit rate of 38.8%, which would top any of his marks from the past three seasons, and his expected wOBA (xwOBA) is 27 points higher than his actual wOBA, so there is likely some positive regression coming there.

Speaking of hard-hit-rate, Cruz has been absolutely destroying the ball as of late, posting the league's third-highest hard-hit-rate (50.8%) over the past 30 days. An unlucky .232 BABIP has held him down during that span, keeping his numbers in check, which provides a perfect opportunity to buy him at a reasonable cost heading into the fantasy stretch run.

Sell Jason Vargas

Jason Vargas' 13-4 record and sparkling 3.00 ERA have been a surprise, to say the least, this season. While some have chalked it up to an improvement in mechanics following Tommy John surgery, a more numbers-driven explanation would be that he has allowed the lowest BABIP of his career since 2012 and has the league's fifth-highest strand rate. He also is the owner of the league's 11th-worst xFIP (4.91), which screams regression in comparison to his ERA.

Vargas' luck has been catching up to him a bit recently, as he has a 4.89 ERA over his past seven starts. While that is bad, his 5.73 xFIP during that span is even more troubling.

With solid season-long numbers and some hype surrounding the Kansas City Royals, right now might be the best time to sell-high on the overachieving starting pitcher. With little to offer in the strikeout department (6.45 K/9) and more regression likely headed his way, Vargas looks like a risky option over the remainder of the season.

Add Carlos Rodon

Carlos Rodon has been volatile enough in his return from the disabled list that he is a tough one to justify spending valuable assets on in a trade, but he is only owned in 22.2% of ESPN leagues, so you shouldn't have to give up much to take a chance on the electric lefty.

Only Corey Kluber has struck out batters at a higher clip than Rodon since the All-Star Break, who has posted a 15.07 K/9 in three starts in the second half. While his 5.23 ERA on the year is nothing to marvel at, Rodon does have a 4.23 xFIP (3.69 in his past five starts), and he should see some improvement in his ERA as the season goes on.

While it is clear that he needs to improve on his control, Rodon has shown unbelievable swing-and-miss stuff and is worth a speculative add in any format.

Sell Gio Gonzalez

Gio Gonzalez has been one of the league's better bounce-back players this season, sporting a 2.66 ERA after he put up a 4.57 ERA the year prior. This would mark the first time since 2012 that he has posted an ERA below 3.50.

While everyone likes a good bounce-back story, Gonzalez's feel-good season doesn't appear to have the legs to last an entire year. His xFIP (4.32) would actually be the worst mark of his career. His 8.35 K/9 would be his worst since 2010, and his 3.67 BB/9 his worst since 2012.

Only four pitchers have a lower BABIP against than Gonzalez (.241), while just one has a higher strand-rate (85.1%), both of which are clear indicators of good luck. While Gonzalez probably isn't as bad as his 4.32 xFIP would suggest, it seems pretty clear that he is not as good as his 2.66 ERA either. If you can sell him based on his season-long numbers or his near-no-hitter in his last start, do so now.

Add/Buy Patrick Corbin

Patrick Corbin continues to be undervalued by the fantasy community, carrying an ownership of just 31.3% in ESPN leagues, in spite of a nine-start streak of less than three earned runs allowed. His 3.04 ERA during that span is mirrored by an impressive 3.40 xFIP and 9.79 K/9, up from 3.94 and 8.42, respectively, on the season.

What's really impressive about his ability to limit runs during that time is that he has done it in spite of a .364 BABIP against. In fact, on the season, only three starting pitchers have a higher BABIP against (.345) than Corbin.

With some better luck on balls in play, Corbin's season-long ERA probably would come a lot closer to his sub-4.00 xFIP. Luckily for us, it doesn't, so he can still be had at a cheap cost.

Sell Jacob Faria

Jacob Faria has been a prime sell-high candidate over the past few weeks, due to a completely mismatched 2.93 ERA and 4.51 xFIP, and now there is a new concern for the young hurler.

Faria has seen a steady decline in velocity in his time in the bigs, with his most recent start marking his lowest average velocity, according to BrooksBaseball.net.

Combine this with the league's fifth-worst xFIP (5.74) over the past 30 days, and there are some real reasons to worry about Faria over the remainder of the season. Fatigue could be setting in for the 24 year-old, who has already thrown 120 innings between Triple-A and the majors this season.

Faria still might be able to be sold high based on his 5-1 record and 2.93 ERA, so if you've enjoyed his strong production this far, it might be worth it to explore the trade market.

Add Brad Hand

Brad Hand was surprisingly not dealt from the San Diego Padres at the deadline, meaning he will hold onto the closer job, a role in which he has been a perfect four-for-four so far with Brandon Maurer out of town. Hand has a dominant 2.00 ERA and 2.75 xFIP (11th among qualified relief pitchers) to match it. When paired with an 11.67 K/9, he has the makings of a power closer with job security, which is a useful option in fantasy, even if San Diego isn't very good.

Hand is still available in over 50% of ESPN leagues, and he could be a difference maker for fantasy teams in need of a closer.

Sell Lance Lynn

Lance Lynn has a respectable 3.20 ERA in spite of an ugly 4.57 xFIP on the year, making him a prime candidate for regression. He's been lights out over his past five starts, with a 1.15 ERA, thanks in large part to a .222 BABIP against. However, his 4.68 xFIP during that span shows that Lynn's ERA is clearly not indicative of how he has actually pitched.

No pitcher has a lower BABIP against than Lynn this season (.225), and he also has the league's eighth-highest strand rate (81.9%).

Lynn's peripherals suggest that if his exceptional luck on balls put in play runs out, he might be nothing but a mid-four ERA pitcher with an uninspiring strikeout rate (7.82 K/9). See if you can sell him based on his recent hot streak.

Buy Masahiro Tanaka

Masahiro Tanaka has been one of the most frustrating starting pitchers in fantasy this season, with a 3.54 xFIP that comes nowhere near matching up with his 5.09 ERA. Over the past 30 days, his peripherals have been even better, as he has the league's seventh-best xFIP (2.63).

He's been able to post a more respectable ERA (3.82) during that stretch as well as the league's second-best strikeout-to-walk rate (21.00).

Tanaka has really cut down on his walks as of late, issuing free passes to just two of the 130 batters he has faced in July, which has definitely helped him turn his season around. He can still likely be had for cheap based on his 5.09 ERA, and he showed just how dominant he can be in his last outing, allowing just 2 hits and striking out 14 batters.