Is it time to overreact yet? This is what many fantasy owners are asking themselves and our writers at RotoBaller, but it's not the question you should be asking. It may be the early portion of a long season, but clearly some trends are forming. The question is: how much longer are you going to wait before pulling the trigger? Disappointing pitchers need to be cut before they irreparably damage your ratios. Sluggers who aren't slugging need to be benched until they get it together. Conversely, overachieving players need to be traded while their value is at its peak. This is why I always suggest picking up a surging player off the wire. Even if you know they are bound to regress, you can at least try to flip them for some type of asset that would have not been available to you otherwise.

Even at this early stage of the 2018 MLB season, scouting players who may be undervalued and re-assessing players who may be overvalued is a weekly exercise that you should pursue. Fortunately, I have you covered. Here are a few players who are good buy or sell candidates based on their current performance compared to ownership levels. This could mean scooping them off waivers if possible or actively seeking a trade to acquire or discard certain players in order to maximize value.

I will typically include at least one player at each key position group (infield, outfield, pitcher). Ownership levels are taken from Yahoo! Fantasy Sports.

Love the strategy of season-long fantasy sports? Live for the short term gratification of DFS? Try Weekly Fantasy Sports on OwnersBox - a new weekly DFS platform. Sign up today for a FREE $50 Deposit Match . Offer expires Thursday night! Sign Up Now!

Underrated Players - Week 4

Wil Myers (1B, SD) 93% owned

How can a player who went 30/20 a year ago be undervalued? It started in the preseason, when Myers' ADP wasn't high enough to crack the top 60 overall players or the top eight first basemen. It's likely because of his .243 average, but also the recency bias of his miserable second half where only steals kept his fantasy value afloat. Myers didn't last three games before hitting the disabled list until returning on April 20. Now that he's back, it may be time to throw a lowball offer to an impatient Myers owner. The power/speed combo is still there, but there's hope that his other stats will improve because he'll have something he didn't have last year: protection. The Padres inked former All-Star Eric Hosmer to a long-term deal to bat third behind Myers. Jose Pirela and Christian Villanueva appear to have breakout potential this year and second-year players Manuel Margot, Austin Hedges, and Hunter Renfroe are more experienced. As the leader of this club, Myers is an offensive weapon that appears to still be underappreciated.

Odubel Herrera (OF, PHI) 59% owned

If you read this series last year, you'll recall that Herrera made the cut on the opposite side very early on. I have not been a fan of his due to inconsistency and poor plate discipline, although I will admit the bat flips are great and the hair is ab fab. This year he looks different. I don't just mean the .333 average either. His 18.3% K% is a career low thus far and he's making a concerted effort to hit the ball to the opposite field. The power hasn't shown up, naturally, but he is capable of pulling the ball and should still be good for around 15 homers when all is said and done. His ceiling may not be the highest, but as a third or fourth outfielder that might be available on you waiver wire in 12+ team leagues, he's a solid contributor for a team that has yet to scratch the surface of its offensive potential.

Mallex Smith (OF, TB) 33% owned

Look, you could tell me that Mallex Smith is going to hit .250 at the end of this season and I'd still be buying shares. Why? Because he'll steal 45 bases along the way. Kevin Kiermaier's injury was just what Smith owners were waiting for, as he's assured an everyday role as long as he's healthy. He's only swiped three bags so far, but the opportunities will be there. Tampa is 10th in stolen base attempts per game already, but that number is sure to climb with Smith on base more often. By the way, he isn't hitting .250 either, it's .373 at the moment. If your league counts steals in any way, shape, or form, add or buy Smith now.

Stephen Piscotty (OF, OAK) 25% owned

It was a slow start for Piscotty, but he's turned it on lately as the A's bats have awakened. He's up to .299 and has five multi-hit games in the past week. Piscotty disappointed last year for well-documented personal reasons, but a move to Oakland might be the remedy to his offensive woes. But Oakland Coliseum is a pitcher's park! Yes, it's currently got the third-worst HR Park Factor for RHB in the league. Guess what? St. Louis is second-worst. He managed to crank 22 home runs and drive in 85 in that park back in 2016. If you can pick up 20+ HR, 80+ RBI and an average close to .300 off the waiver wire at this point in the year, shouldn't you do it?

Andrew Heaney (SP, LAA) 8% owned

You may recall that Heaney was once a top-flight prospect and top-10 draft pick for the Marlins. It's only fitting that he's on the Angels' pitching staff now because he's battled injuries for the last two years. Heaney had Tommy John surgery in 2016, pitched just 21 innings last year as he recovered and then gave a good scare to the team by suffering elbow inflammation in the spring. It proved to be nothing serious and he came back to toss five mostly effective innings against the Royals. A bad showing against the Giants will scare people away, but 11 K in his first seven innings is a sign that his stuff is still there. It will take a little time to round into game shape, but you can still pick him up for some cheap help in the strikeout department.

Overrated Players - Week 4

Ozzie Albies (2B, ATL) 90% owned

Heresy! Albies is a young stud on an upcoming team and a lock for Rookie of the Year! I'm not arguing against any of that. Keep in mind that the focus of this series is to weight perception vs reality. Albies is currently the sixth-best hitter and 10th-best fantasy player in 5x5 roto leagues for 2018. It's also three weeks into the season. After cranking homer number six on Friday night (against Thor no less), Albies is only three HR away from his career high. Seriously. Never having reached double-digit home runs in the minors, this power surge isn't just surprising, it's unsustainable. A HR/FB rate over 20% is due for regression naturally, but it's also more than double his career mark through four years of professional ball.

Albies' value was supposed to come from a high batting average and the prospect of 15-20 steals. He's swiped just one bag so far and 20 seems like a stretch. If you've gotten the best out of him already, why not bail now before the drought hits? His value will not be higher than it is now, so add him to your trade block and watch the offers pour in. Some of our readers are telling me they've been offered players like Yu Darvish or Robbie Ray. Given the dearth of top-notch SP, that's a deal you should be happy to accept.

Marwin Gonzalez (1B/2B/3B/SS/OF, HOU) 76% owned

Believe me when I say that seeing a player with that much positional eligibility makes me feel all tingly inside too. Marwin Mania was great while it lasted, but you had to know it wouldn't carry over to this year. He's slashing .190/.288/.286 with just one home run. His strikeout rate is also up to a career-worst 24.3%, although his walk rate is at a career-best 12.2% too. Now that Yuli Gurriel is back, everyday playing time is not guaranteed. There's bound to be an injury-plagued team in your fantasy league looking to utilize a player like Gonzalez who can plug multiple holes.

Kyle Schwarber (OF, CHC) 82% owned

Schwarber is showing signs of life, collecting four hits and five RBI in the last two days. Good, now trade him. Expectations will always exceed production for this postseason hero, but the reality is that he's a career .223 hitter who who can't hit lefties (.156 AVG and 65 K in 147 AB). He's no longer eligible at catcher or anywhere other than outfield, so we're left with someone who's really not more valuable than last week's overrated OF pick, Adam Duvall.

Shane Greene (RP, DET) 62% owned

Blowing a save isn't cause enough to push the panic button on a closer, even if it is against the lowly Royals. People who are ready to start selling Kenley Jansen (seriously, don't do it) just can't be reasoned with, but the rest of us know better than to overreact. In Greene's case, his value was shaky to begin with. Closers on non-contenders are usually prime fodder for big market clubs to stash in middle relief at the trade deadline. With future closer Joe Jimenez pitching lights-out this season (zero ER over 7 2/3 innings and a 3.50 K/BB), it's only a matter of time before the job is his. Deal Greene to any owner hungry for saves and pickup Bud Norris instead.

More Risers and Fallers