The first week of the season is nearly at its end. Are you ready to cut bait on some of those later round picks already? Dying to scoop up that utility player off to a hot start? Itching to grab that setup man next in line for saves once the closer loses his job? It may be early to start revamping your roster completely, but it's never too soon to get a competitive advantage over your leaguemates.

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.

Early in the season, my values will be based more on ADP than performance due to small sample size. I will include at least one player at each key position group (Infield, Outfield, Starter, Reliever). Ownership levels are taken from Yahoo!

Underrated Players - Week 1

Eduardo Nunez (3B/SS, SF) 88% owned

Nunez is almost universally owned, but profiles more as a low-end SS or CI/MI on most fantasy teams according to his draft value. Even after a torrid first week of the season, including a .879 OPS and three steals in five games, he was in less than three-fourths of starting lineups Friday night. Nunez's breakout year has been taken with a large grain of salt by the fantasy community, despite the fact the signs pointed to him trending upward. Nunez had improved his ISO for three straight seasons and his speed was always there. The only difference was that he finally got the chance to play every day. Now, on a better ball club and hitting sixth behind Buster Posey and Brandon Crawford, he should see his RBI numbers jump up. Nunez's ADP was a full 60 picks behind Jean Segura, yet Segura stole seven fewer bases in 84 more at-bats last year. Both players are in new uniforms to start the season, but Nunez should be the beneficiary as Segura moves from hitter's haven Arizona to spacious Safeco Field. The fact that Nunez seems more than comfortable in San Fran should make you an interested buyer.

Nomar Mazara (OF, TEX) 81% owned

Mazara's massive six-RBI game may boost his value a bit more, but it may not be too late to acquire him in a fair deal. Pre-draft rankings and ADP have him as a fourth outfielder in mixed leagues, but he is capable of performing like a second outfielder. As a rookie, Mazara hit 20 HR and 64 RBI, which are numbers he can easily build upon in a loaded Rangers lineup. I'd take him any day in a straight up swap for players like Joc Pederson or Yasmany Tomas, both of whom were drafted ahead of Mazara. Those players will get their share of homers, but not much else. Since speed isn't a consideration, let's look at the power value of each. A quick look at OPS tells us that Pederson's .847 and Tomas's .820 dwarf Mazara's .739 OPS from 2016. Pederson has swatted 26 and 25 HR the last two seasons and Tomas powered up for 31 HR last season after hitting just nine the previous season. Pederson sports a career .223 average whereas Tomas is at .271. Mazara finished at .266 in his debut year, but his minor-league record supports the idea that he will sit between .270-.290. With Tomas, we only have numbers from the Cuban National Series before 2015 to fall back on. Keeper league owners should already be heavily invested in Mazara, but he could be underestimated in single-season leagues.

Matt Harvey (SP, NYM) 94% owned

The Dark Knight Returns? Too cliche maybe, but it seems appropriate. Harvey's first start of 2016 went nearly as well as fantasy owners could have hoped for. He pitched 6.2 innings and allowed three hits, two of which were solo homers by Matt Kemp unfortunately. The best news is that he didn't walk a single hitter and his velocity remained near 95 MPH. Thoracic Outlet Syndrome isn't to be taken lightly, but when you compare where he is to Tyson Ross, who is still in extended Spring Training, it is more than encouraging. Chances are that whoever drafted Harvey in your league (assuming it wasn't you) is high on him to begin with and may not want to part with him so easily before seeing more. Try to strike a deal before he deals another quality start against the Phillies on Tuesday.

Jeremy Jeffress (RP, TEX) - 12% owned

Even if you didn't see Sam Dyson's early-season implosion coming, you have to acknowledge it wasn't a foregone conclusion Dyson would finish the year as the closer in Texas. Jeffress should have been one of the top handcuffs taken, not just by Dyson owners, but in AL-only leagues. His paltry ownership rate could make him one of the better long-term waiver adds this season if he does inherit the job. This assumes he can be as effective as he was in Milwaukee through the first half of 2016, when he saved 27 games and posted a 2.22 ERA and 3.19 K/BB, rather than the 1.0 K/BB he put up in Texas. Then again, if you're a Dyson owner, you weren't hoping for outstanding strikeout rates from your closer in the first place. Keep a close eye on Jeffress in your league.

Overrated Players - Week 1

Greg Bird (1B, NYY) 77% owned

Too soon? You shouldn't hit the panic button on anyone right now, but Bird is doing exactly what fantasy owners were afraid of. He has one hit in 16 at-bats and is yet to homer. Granted, it's been four games... but those all came at Tampa Bay, not Boston. He faced the likes of Chris Archer, Alex Cobb, and Jake Odorizzi; only Archer could be considered a top-tier pitcher. Three of those four games resulted in an 0-for-4 performance and he has a total of seven strikeouts in those 16 AB. While Bird's blazing Spring Training escapades seem like a distant memory right about now, this may actually be a great buy-low opportunity. If you have a trigger-happy owner who is ready to dump him, pull the trigger on a deal for one of your low-end CI or scoop him up on waivers if he's already been dropped. He may not pan out, but it's way too soon to make that judgment since the Yanks are willing to let him earn the starting gig.

Adam Eaton (OF, WAS) 93% owned

Eaton was drafted as a top-30 outfielder and is being treated by some as A.J. Pollock Lite. He isn't. Eaton's speed has never resulted in a 20-steal season in the majors, nor has he ever reached 15 HR. Eaton has great run-scoring potential if he sticks near the top of the Nats lineup as he has lately, but seeing him at the sixth spot early on had to worry fantasy owners. Give me someone like Odubel Herrera instead, who in his second full season already surpassed Eaton's best power/speed numbers and is hitting third. Their slash lines were nearly identical last year (.284/.362/.428 for Eaton, .286/.361/.420 for Herrera), but Herrera has the higher ceiling in counting stats.

Vince Velasquez (SP, PHI) 87% owned

In the overreacting-to-his-first-start-of-the-season category, Velasquez is a prime candidate. He showed his massive strikeout upside by punching out 10 Nationals in just four innings. The problem, as you can imagine, is that he only lasted four innings after giving up three walks, five hits, and four runs. Expecting him to maintain high K totals is not unreasonable at all - his 11.2% SwStr% supports that. Expecting him to suddenly start showing consistency, when he allowed four runs or more in one-third of his starts last season, is a bit premature. If you're in a single-season league, you don't necessarily need to sell low, but temper your expectations.

Dellin Betances (RP, NYY) 86% owned

This isn't Yankee-bashing time, but the fact that two Yanks are overvalued is probably indicative of big-market bias. Betances is a lights-out reliever who strikes out an outstanding 14.3 per nine over his brief career. The problem is that he isn't a closer and won't be any time soon. The Yankees already have the premier closer in the league in Aroldis Chapman, so if you're in a standard 5x5 roto league, there is really not much incentive to own Betances if you aren't a Chapman owner holding onto his handcuff. If your roster goes deep enough that you slot three or four RP, then he can help in K and ratios for sure. But unless your league counts holds or K/9, he won't pitch enough innings to earn a good ROI on his 15th round ADP (12-team leagues). If you are holding onto him in a 5x5 without Chapman in your pen, see what you can get in exchange from the Chapman owner who may want to hedge his bet. Remember, I'm not saying Betances is overrated as a player, just overvalued in many fantasy formats.