We're fresh off Memorial Day weekend, which serves as sort of a measuring stick for fantasy baseball owners. By this unofficial summer-starting holiday, we're deep enough into the season that your league's overall standings and individual category rankings carry some weight.
If you're at or near the top to date, well, congrats on a great first two months, but the real test will be holding on to your lofty status. If you're lower in the standings, just know there's all kinds of time -- like four months -- to make up ground.
Either way, you always should be looking to improve your roster and address specific areas of need or weakness. The most rewarding path to that? Trade for a player -- like one of these -- at below-market value, then watch the production rise as summer really starts heating up.
Josh Donaldson, 3B, Blue Jays
Much of the conversation regarding Donaldson so far this season has been trade speculation (he's a free agent come November) and injury updates (he dealt with right shoulder inflammation in April, and more recently he exited Monday's game with left calf tightness). His actual on-field performance, meanwhile, has left something to be desired.
Donaldson is hitting just .234 with five homers and 16 RBIs -- not quite what was expected when the former American League MVP Award winner was selected in Round 2 or 3 on draft day. If you want to make the 32-year-old slugger's owner even more concerned, point out that Donaldson is striking out at a career-high 27.7 percent rate, while his exit velo (89.7 mph) and launch angle (9.7 degrees) also are noticeably below his past few peak seasons.
That doesn't pain the prettiest picture of a player to buy low, but you have to remember Donaldson's production has been diminished due to injury. He's also still walking at a strong clip (13.2 percent), which is a good sign, and he's had similar injury-riddled slow starts before.
After battling injuries early last year and seeing his OPS dip to .778 in late July, Donaldson finally got healthy and stormed to a monstrous .302/.410/.698 line with 22 long balls and 47 RBIs over his final 50 games. Expect Donaldson to make a contract push with a strong second half.

Nelson Cruz, DH, Mariners
The Mariners have been one of baseball's hottest teams of late, despite enduring the losses of Dee Gordon and Robinson Cano … and surprisingly getting very little out of Cruz, one of the sport's most consistent sluggers in recent years.
While the veteran slugger has managed a reasonable nine home runs, he owns a .223 average and has scored only 14 runs after averaging .292 and 92 in those categories in his tenure with Seattle (2015-17). It's fair game at this point to approach Cruz's owner and question whether the longtime DH is slowing down as he closes in on his 38th birthday on July 1.
You, on the other hand, know that Cruz has endured some bad luck when it comes to both his health -- a DL stint for a sprained right ankle in early April, then a bizarre rash of hit by pitches (on his foot then elbow) in mid-May -- and his .234 BABIP, which ranks among the 20 lowest in baseball. Put simply, his numbers are down because of a dearth of opportunity and a surplus of misfortune.
Whether Cruz can bounce all the way back is a bit "TBD," but it's worth taking a shot on a player whose raw power stats (average of 42 HR and 106 RBIs from 2015-17) and underlying batted-ball profile (51.7 percent hard-hit rate -- Top 20 in MLB) mean he could get hot in a hurry.

Jon Gray, Rockies, SP
Own a Rockies pitcher in fantasy?! Yoiks. That idea almost always has proven to be a regrettable one. In fact, that's the case with Gray himself, at least through the first two months. His owner is staring at a 5.40 ERA and 1.41 WHIP and wondering, "Why did I ever think it would be a good idea to roster someone who pitches at Coors Field half the time?"
So why would you consider trading -- actually giving up something! -- for a Rockies pitcher? For one, the cost of acquisition should be low at this point. For another? Gray has been throwing the ball much, much better than his surface stats show.
To wit, the 26-year-old has been more than a little unlucky, as his MLB-high .368 BABIP screams. His FIP, meanwhile, is strong at 3.16, meaning Gray also has the largest gap (2.24) between his ERA and his FIP. Last but not least, Gray's batted-ball data indicates opposing batters should be hitting .249 with a .395 slugging percentage against him -- not .283 and .450, respectively.
As much as Coors Field might scare you off, it actually should help you land Gray at a cheaper price if his owner wants to unload. Besides, Gray pitched better at home (3.13 ERA, 1.22 WHIP) than on the road (4.06, 1.35) in 2017, so he's shown the ability to overcome even baseball's toughest hitters' park.

James Dozier, 2B, Twins
Consider Dozier's 2018 numbers to date: .237 average, 29 rubs, seven homers, 20 RBIs, two steals. That's … fine. It's not bad, but it's not near expectations for a player who has been among the most productive at his position the past two years. It's also disappointing for Dozier owners in light of the fact that the 31-year-old started off this season with a 17-game hit streak.
Now consider why you want to make a play for Dozier ASAP. Here are his fantasy stats through May each of the past two campaigns:
2016: .202 average, 21 runs, five homers, 17 RBIs, three steals
2017: .249 average, 24 runs, eight homers, 22 RBIs, eight steals
Those digits don't look all that impressive, either. And yet, Dozier went on to bat .269 while averaging 105 runs, 38 homers, 96 RBIs and 17 steals across 2016-17. If you're worried about Dozier's third straight slow-starting season, don't be. If the Dozier in your league is, make your move.

Vince Velasquez, SP, Phillies
Velasquez has been anything but consistent as a big leaguer. He looked like a breakout candidate early in 2016, highlighted by his 16-strikeout masterpiece shutout in his second start that year. Alas, he gradually saw his performance decline while also dealing with various injuries that limited him last year to all of 72 innings, along with a 5.13 ERA and 1.50 WHIP.
When Velasquez opened 2018 with a 5.70 ERA through six April starts, it was hard to blame his owner for wanting to move on.
Here's hoping that ugly beginning remains firmly in the front of said owner's mind. This month, the soon-to-be 26-year-old is sporting a 2.30 ERA, 1.21 WHIP and a stellar 11.9 K/9 over 27 1/3; frames. Oh, and Velasquez also owns the biggest disparity (minimum 750 pitches) between wOBA (.320) and xwOBA (.279), indicating that he's actually been unlucky -- and his turnaround is at least somewhat for real.
Given Velasquez's inconsistency and checkered injury history, don't expect any miracles. But all of that should be baked into his buy-low case. This might be an enjoy-it-while-you-can trade target, and sometimes that'll do, especially when you don't have to give up much of anything to get a boost.