Last summer, Roster Doctor tackled five of the biggest underachievers of the season to that point. The idea was to highlight players who looked unpalatable to toxic, but still warranted pickups in your fantasy league.

That post came out about the halfway point of the season, so it provides a useful before-and-after snapshot of the upside (and downside) that early slumpers can provide for shrewd shoppers. Because we’re about accountability here (and we’ll try to do this for other features when possible), you can check the sidebar to see how those suggestions panned out.

This year, we’re covering Buy Low, Buy Lower, and Buy Lowest candidates a few weeks earlier. The goal is to find players who’ve exasperated their owners so thoroughly that they’ve either been dropped and are there for anyone to pick up, or could be had cheaply in trade. Players like Matt Cain, Rick Porcello, and Jarrod Parker have already started to turn things around after miserable starts. Who’s next?

BUY LOW

Rickie Weeks: Fourth inning Wednesday night, Weeks lines a ball to center, looking like he’s got a sure hit. But Aaron Hicks sprints about 14 miles, dives, and makes a ludicrous catch, the latest robbery for one of the most spectacular glovemen in the game. It’s been that kind of year for Weeks, hitting .181/.286/.275 despite smacking more line drives than in any other full season in his career. Other elements of his batted-ball profile are telling, though, including the highest ground ball rate he has ever posted and the second-lowest home run–per–fly ball rate. Still, there are enough conflicting elements to suggest some bad luck might be in order: Weeks is striking out more than ever (29.6 percent K rate), but he’s also posting his third-best walk rate ever, and his lowest batting average on balls in play.

The biggest thing working in his favor, though, is the same factor that landed four other players on this list: track record. Though he has struggled with injuries at various times in his career, Weeks appears healthy this year. And when healthy, he’s been one of the most productive fantasy second basemen around. Weeks did struggle last year, posting some of the worst numbers of his career in a DL-free campaign. But even then, you could split his season into two distinct halves, as evidenced by the numbers shown in the sidebar (Weeks is one of two repeat buy-low picks from last year — he was, in fact, a buy-lowest in 2012). Even with the emergence of unexpected success stories like Kelly Johnson, Jedd Gyorko, and Daniel Murphy, the second-base position is still filled with dregs, making it especially tough to find a quality player in deeper leagues. Weeks is a good, cheap option if you’re looking to fill that void.

Miguel Montero: The fifth-most productive catcher in the majors last year has delivered sub-replacement level results this year, hitting just .190/.280/.276. There are two distinct problems here. First, he has shown little to no pop, posting the lowest Isolated Power mark in any full season at .086; a career-low 6.8 percent home run–to–fly ball rate is partly responsible there.

The more jarring number is a .222 batting average on balls in play, down 89 points from his career average and an amazing 140 points from last year’s mark. Even with a dip in his line drive rate, this looks like one of those sample-size flukes that even two months can’t properly explain. As with second base, there’s a scarcity issue at catcher for deeper-league fantasy players, painfully so if you’re in a league that makes you start two players at the position. Montero is hitting near the bottom of the order while suffering through this slump, but manager Kirk Gibson has trusted him to hit in the middle of the order in the past, with 200 plate appearances in the cleanup spot last year — when Justin Upton was still on the team. A hot streak would bump up his numbers and maybe elicit a lineup promotion, too, making Montero an intriguing upside play for the next four months.

BUY LOWER

Edwin Jackson: This one’s easy: No way do Jackson’s peripherals support a 1-7 record with a 6.11 ERA. Granted, the Cubs’ anemic offense isn’t going to offer a ton of run support. Still, Jackson is posting the highest strikeout rate of his career at just less than a batter per inning, inducing more ground balls than he has in seven years, allowing fewer homers than his career average, and producing a profile that’s netted career bests in FIP (3.69) and xFIP (3.67).

Unfortunately, the luck dragons have bitten him in the ass. We’ll cite BABIP one more time, because his .341 mark is tied for his career high and is 33 points above his career average. The biggest fluke is Jackson’s tiny 56.4 percent strand rate. With nobody on base, hitters have batted .267/.320/.422 against Jackson; with runners on base they’ve hit .286/.385/.440; with runners in scoring position they’ve hit .292/.408/.468. It’s unlikely that a pitcher in his 11th major league season would’ve suddenly succumbed to unfixable jitters, or forgotten how to pitch from the stretch, which means some positive regression probably lies ahead. Jackson isn’t an elite option even in the best of times. But in standard leagues, he’ll be worth streaming against the Marlins and Mets of the league. And in deeper leagues, he’s worth a pickup.

B.J. Upton and Jason Heyward: Oy. Let’s start with Heyward. The offensive beast everyone was expecting hasn’t yet materialized. We’ve seen glimpses, including the 27 homers he smacked last year and the .393 on-base percentage he posted in his rookie year. But Heyward hasn’t yet had a season where he’s consolidated all his skills into one big offensive outburst, while also staying healthy. A bout of appendicitis shoved him to the DL earlier this season, and it’s possible he’s still getting his timing down after missing nearly four weeks. Then you remember that Heyward is only 23 years old; that his power is so prodigious the Braves had to put up special nets to protect the cars he was smashing in the parking lot at spring training; that he’s a stolen-base threat who swiped 21 bags last year; and that his terrific defense and history of snapping out of ugly slumps should keep him in the lineup while he works it all out. Of all the players on this list, he might be my favorite buy-low choice.

On a park- and league-adjusted basis, only the hapless Jeff Keppinger has fared worse than Upton this year. His 34.6 percent strikeout rate is the third-highest in the majors; he’s hitting for less power than he ever has since becoming an everyday player; he’s near the bottom of the league in line drive rate; he has hit more popups than anyone else in baseball; he’s swinging and missing more than ever; he’s falling behind 0-1 more than ever; he’s stealing fewer bases than ever before even after adjusting for his horrific OBP … you name the indicator, he has been awful. Even after acknowledging a two-month sample size and a .204 BABIP that’s partly due to luck as well as poor batted-ball trends, we might be seeing real skills erosion at work.

Upton has had a very strange career, one that saw him post his best offensive results (a .386 wOBA) in his first full season, then decline ever since. What you typically get with Upton — even after that decline — is something close to a 30-30 season, with a low batting average and lots of strikeouts. We’re recommending him on that basis, figuring that even ugly Upton can help plenty of fantasy teams. So by all means, you should still target Upton if he’s available at 50 cents on the dollar from his draft price, accepting the low average while anticipating a pickup in power and especially speed. But at 75 cents or higher, you might find better buy-lows worth pursuing.

BUY LOWEST

Ike Davis: Every player is going to look bad when he’s not hitting. Striking out rarely looks elegant. Neither does popping out or flying out. But Davis’s struggles go beyond mere bad results. Watch the Mets on any given night and you’ll see Davis swinging out of his shoes, dead set on pulling the ball like a Home Run Derby contestant. That’s how you end up with a 33 percent strikeout rate, by far the highest of his relatively short career, and also one of the highest for any hitter this season. That’s also how you end up with one of the league’s worst contact rates on pitches out of the strike zone. He’s walking less than at any point in his career, making contact on fewer pitches in the strike zone than he ever has, and swinging and missing more often than ever before. No surprise then that he’s hitting a hideous .160/.242/.245, making him the third-worst hitter in the majors on a park- and league-adjusted basis.

When things are going that badly, you look for something, anything that might spark a bit of hope. On Wednesday, Davis delivered just his fifth multi-hit game of the year. Making the event even rarer was how it happened: on a single to center, and a single to left-center. OK, OK, probably too small a sample size to mean anything. A better indicator would be what happened to Davis last year, which is part of the reason he’s the second repeat player on this list. You can see his huge post–July 2 turnaround in the sidebar. For an even more dramatic angle, consider what Davis was hitting at this time last: .170/.228/.296. He hit .253/.341/.536 for the rest of the year, with 27 homers, 21 doubles, and 69 runs knocked in. In shallow leagues, Davis is almost certainly on waivers. In deeper leagues, he can be had for a song. Offer a handful of dryer lint and see if he can do it again.