Stop the presses - Ronald Acuna has arrived! The presses have actually been kicking into overdrive since he amazed the baseball world with a wicked single and a couple of really, really long fly ball outs in his Major League debut. Oh, he hit a mammoth home run in his second game too. Like any sane analyst, I'm not going to project him as being undervalued or overvalued until I actually watch him hit for a reasonable amount of time against big league pitching in a non-Spring Training situation. Let's instead look at some veterans who aren't getting the spotlight, but could be worthy of your attention.

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.

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Underrated Players - Week 5

Marcus Semien (SS, OAK) - 55% owned

You could make a strong case that the entire Oakland offense is undervalued, but Semien seems to be the most overlooked. His propensity to get injured and hit below .250 have hurt his profile, but he may be finally taking the next step. Semien is hitting .278, which is 30 points above his career average and is riding a six-game hitting streak. Although he has a slightly elevated .338 BABIP, it's supported by a jump in his hard-hit rate to 37.3%. He may never approach .300, but he doesn't have to. You may not realize that Semien, on the supposedly light-hitting Athletics, is fourth in the majors with 22 runs scored and his 13 RBI ties him for eighth among all shortstops. Dansby Swanson became a hot add last week, jumping up to 69% ownership, but Semien is providing equal value and is more likely to sustain it, as Swanson's .403 BABIP is sure to regress.

Domingo Santana (OF, MIL) - 66% owned

Now is the time to strike. Santana was probably overvalued in fantasy drafts this preseason, although not for the reason you might think. The issue here isn't talent; it's opportunity. He didn't luck into 30 home runs last year - he flexed plenty of power in the minors when he was an Astros prospect. The crowded Brewers outfield has made playing time an issue, temporarily alleviated by the Christian Yelich injury, only to resurface again last week as he sat for three straight games. A .228/0/4 triple-crown line makes him a player some have given up on altogether, but he actually had a lower average in April of 2017 (.197) before warming up in May (.322). His line drive rate is down, but most of his plate discipline peripheral stats are similar to last year. I doubt he forgot how to hit the ball over the fence, so it's way too early to push the panic button.

Plus, a glimmer of hope for his playing time just arrived in the form of Eric Thames' thumb. Jesus Aguilar will take the majority of playing time at first, but Santana will continue to be mixed into the lineup and should see about four or five games a week. If you drafted him as an OF2 or OF3, you're stuck with him anyway so you may as well hold on and hope he heats up. If your outfield is an injury-riddled mess or you're looking for a lottery ticket, Santana's value probably won't get much lower than it is now.

Michael Taylor (OF, WAS) - 41% owned

Taylor is currently on pace to steal 55 bases this season. That's unlikely to happen, even if he manages to play every day from here on out. With Adam Eaton returning any day now (fingers crossed), this might seem like the time to ditch Taylor. Unless you noticed that the Nats have also been rolling with Moises Sierra and Andrew Stevenson in the outfield this season, so it's not as if his path to playing time is truly blocked. Taylor won't hit for average, but the speed is real, and he's increased his walk rate substantially (10.5%) to give himself more opportunities to run. With all the injuries the Nats still have and the dearth of true base stealers, you can't ignore a guy who's second in all of baseball in a core category.

Drew Pomeranz (SP, BOS) - 59% owned

It may look like Pomeranz is a shell of himself, but here's where patience will pay off. Pomeranz predictably had some rust to shake off in his first start of the year against an Oakland lineup that I just declared as underrated. Tampa seemed like an obviously easier draw for his second assignment on Friday night, but this is a team that had scored 53 runs in the last week alone! He gave up four runs over five innings, all courtesy of three long balls. Pomeranz has never had much trouble allowing home runs, keeping a tidy 0.98 HR/9 last season and just over one HR per nine IP for his career. For perspective, that home run rate from 2017 placed him within the top 20 among qualified pitchers, better than Max Scherzer and Chris Sale. Pomeranz will be fine within another start or two, so take advantage of his low stock if you could use a guy who can rack up wins and strikeouts at the back of your rotation.

Greg Holland (RP, STL) - 61% owned

No saves and an ERA over 5.00? Is that what I spent all my FAAB for? Many fantasy owners are asking themselves this question as Holland has not been delivering any ROI early this season. The key word there is early. He didn't have a team or a chance to go through full Spring Training, so a veteran like him with injuries in his recent past will take some time to warm up. He's thrown three straight scoreless frames, however, and could be ready to take over the closer role once May hits. That is why they brought Holland in, after all. It's not as if the Cards spent $14 million for him to work the eighth inning all year long. Conversely, while he won't get a write-up here, flip Bud Norris as soon as possible for pretty much anything you can get.

Overrated Players - Week 5

Brandon Belt (1B/OF, SF) - 64% owned

Do we honestly think he's going to keep this up? This isn't a post-hype breakout like Jose Martinez or Justin Smoak a year ago. Belt has been a fixture in the Giants' starting lineup since 2012, and he's already at the ripe age of 30. As a player who has never finished with 20 HR, 85 RBI or a .300 average, why now? Belt's having a terrific week, and he's an OBP machine, but if someone in your league thinks "this is the year" he suddenly becomes a slugger, gladly deal him for a younger, better version like Josh Bell.

Yasiel Puig (OF, LAD) - 78% owned

Now that he's in his age-27 season, you have to wonder if we'll see Puig live up to his full potential. Then again, have you considered that we may already have? The temperamental outfielder stroked 28 homers and stole 15 bases last season while helping the Dodgers to the NL pennant. This year couldn't be more strikingly different for both parties. Puig is yet to go deep and owns a .195 AVG and .499 OPS. There's plenty of time to turn things around, but the Dodgers may be less patient than we think. We already know he doesn't bring good vibes inside the dugout, so if his bat isn't doing the job, then he could find himself on the outside looking in. Puig's contract expires at the end of this year, so he isn't long for the team anyway. He could soon become a reclamation project for a rebuilding team (Miami?) willing to take a chance for a discounted price. In the fantasy world, don't hold your breath waiting for a resurgence.

Dallas Keuchel (SP, HOU) - 98% owned

Sometimes listening to the wisdom of our own Real Talk Raph is all you really need. In a preseason conversation on SiriusXM, Raph proclaimed his complete lack of interest in Keuchel as a fantasy asset due to a lackluster strikeout rate and reliance on his defense that leads to fluctuations in value. Keuchel is looking more like his 2016 self than 2015 or 2017. Notorious for his ability to induce grounders and soft contact, his 56.6% GB% is still above league average, but 10 points lower than last year. He was rocked by the Athletics on Friday, allowing six ER and three homers, including a towering shot by Chad Pinder. It may have made more of an impact on me since I was actually able to watch the game in person at Minute Maid Field, but that doesn't change the fact that Keuchel appears to be continuing his trend of only being fantasy-relevant in odd years. Hope for a good start next time out and then sell.

Ronald Acuna (OF, ATL) - 85% owned

OK, I couldn't resist... He may very well be Rookie of the Year, but if someone in your league is ready to trade you Giancarlo Stanton or Trea Turner for him, just take it. I'll take 50 HR or 50 SB over any rookie any day.

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