The 2016 Major League Baseball season is at the quarter pole and the second month of the campaign is nearly over, which means the Aug. 1 trade deadline is looming on the horizon for all 30 teams. It’s time, then, to highlight several players who entered the season as prospective trade candidates and have since weakened their respective values, be it through poor performance, injury or both. All of these players generated trade buzz during the winter, and each is a member of a team that was expected to be a deadline seller entering the season and hasn’t done anything to prove that belief wrong in the initial 40-plus games.

Athletics

Billy Butler: The A’s had talks with other teams about trading Butler over the winter, but their hopes of dealing the designated hitter are all but gone now. Butler, who’s currently making $10MM and is owed the same amount in 2017, has declined significantly since his heyday in the Royals’ lineup from 2009-13 and is hitting .209/.243/.284 without a home run in 70 plate appearances this year. Since 2014, his swan song in Kansas City, the 30-year-old Butler has batted a meek .258/.319/.379 with 24 homers in nearly 1,300 PAs, and given that he provides negative value in the field and on the base paths, that type of offensive output isn’t going to appeal to anyone. It remains baffling that the A’s signed Butler to a $30MM deal in 2014, and now they’re stuck with him.

Sonny Gray: While the A’s fielded plenty of inquiries on the right-hander during the offseason, they made it clear – at least publicly – that he wasn’t available. “We’ve been adamant with teams that we want to hang on to Gray,” executive vice president of baseball operations Billy Beane said in January. Prior to that comment, general manager David Forst stated in November that the A’s weren’t going to move Gray, saying, “As soon as you trade a young, healthy really good pitcher, you’re looking for another one.” Still, after back-to-back full seasons of ace-like production, four years of control over Gray, 26, would’ve landed Oakland a sizable haul. Gray is now in the midst of the worst year of his young career, having compiled a 6.19 ERA, 7.69 K/9 and 4.5 BB/9 in 48 innings, and the club placed him on the DL earlier today with a strained right trapezius. Given the weakness of the upcoming offseason’s free agent pitching market, teams would’ve kept hounding the A’s about Gray had he continued his effectiveness and stayed healthy this year. Neither of those things has happened, though, which decreases the already dubious odds of the A’s parting with Gray before the deadline.

Braves

Erick Aybar: When the rebuilding Braves acquired Aybar from the Angels as part of the Andrelton Simmons package, their hope was that he’d serve as a sturdy shortstop bridge between Simmons’ reign and the Dansby Swanson/Ozzie Albies era. Aybar has instead been the worst player on arguably the majors’ worst team, having hit .175/.216/.204 in 151 trips to the plate. The 32-year-old’s 7 wRC+ is easily last among qualifying hitters (his closest company is at 43), as is his minus-1.6 fWAR. The Braves had a high asking price on Aybar as of March, but they’ll have difficulty finding anyone willing to take the $8.5MM infielder in the last year of his contract if his play doesn’t substantially improve.

Nick Markakis: The Braves reportedly had opportunities to trade Markakis last winter and in 2015, but they elected to retain the right fielder instead. Considering that Markakis is on a $10.5MM annual salary from now until the end of 2018, Atlanta might regret not dealing the 32-year-old. Since joining the Braves last season, the power Markakis showed in Baltimore from 2006-14 has disappeared. In 871 PAs with the Braves, Markakis has totaled just four home runs – two fewer than Giants pitcher Madison Bumgarner, who has amassed 765 fewer PAs – and logged the majors’ fifth-worst ISO (.083). To Markakis’ credit, he has managed to produce a decent 105 wRC+ with the Braves and has gotten on base at an impressive 36.9 percent clip, but an aging, well-compensated, power-devoid corner outfielder who doesn’t grade well defensively simply doesn’t have much value.

Padres

Andrew Cashner: A report in December stated that the A.J. Preller-run Padres were pushing to move Cashner prior to his contract year, in which he’s making $7.15MM. However, the team was unwilling to deal the right-hander for then-Diamondbacks center fielder Ender Inciarte, Arizona GM Dave Stewart said. Even though Inciarte has struggled this year in Atlanta (he’s hardly alone), acquiring five years of control over him for one season of Cashner would’ve been a boon for the Padres. Instead, Cashner stayed in San Diego and has begun 2016 with 34 2/3 innings of 4.93 ERA/4.42 FIP/4.61 xFIP ball. The injury-prone Cashner – who’s on the DL with a minor hamstring issue – was better last season in posting a 4.34 ERA/3.85 FIP/3.84 xFIP, but he hasn’t been particularly effective at preventing runs since 2012-13 (3.33 ERA in 221 1/3 frames). Cashner’s trade value isn’t dead, but barring a turnaround after he comes back from the DL, odds are the Padres will have a tough time netting a return as enticing as the one they could’ve gotten for him over the winter. If the Padres aren’t satisfied with the offers they receive for Cashner this summer, they could keep the 29-year-old and extend him a qualifying offer after the season. The risk there would be that Cashner would actually accept the $15.8MM offer, as multiple players did last offseason. That would force the Padres to continue with Cashner at a salary worth more than double what he’s making now. Worse, the rebuilding club wouldn’t receive a first-round pick for him as compensation.

Matt Kemp: Nick Cafardo of the Boston Globe reported at the outset of this month that Kemp’s productive April had improved his trade value, but the right fielder has canceled that out with a .169/.173/.312 line in 81 May PAs. Long a below-average defensive outfielder, Kemp’s value throughout his career has been tied to his bat. Kemp’s offensive output has fallen off in recent years, however, and his value has cratered as a result. Since compiling a 3.2-fWAR campaign in 2012, the 31-year-old has been worth a combined 1.2 fWAR while hitting an unspectacular .270/.319/.459 in 1,714 PAs. It’s nice that Kemp continues to show power – he has already accumulated 10 home runs this season after smacking 20-plus in each of the two previous campaigns – but his walk rate (2.3 percent) is alarming and far worse than his career mark of 7.6 percent. Further, the two-time All-Star is being paid commensurate to the MVP candidate he once was. Kemp will collect $21.5MM per annum through 2019, and the Padres were reportedly hesitant to eat a lot of money to deal him over the winter. Now, as an over-30, defensively challenged player who has clearly seen better days at the plate, it appears the Padres could be stuck with Kemp.

Tyson Ross: Unlike Cashner, the right-handed Ross has been consistently superb at preventing runs. Since 2013, his first season as a Padre, Ross has pitched to a stingy 3.13 ERA over 522 innings while averaging more than a strikeout per frame. Unfortunately, the slider-heavy Ross hasn’t pitched since Opening Day because of a shoulder injury. The 29-year-old still hasn’t resumed throwing, which means his return isn’t approaching. Even if Ross were to come back close to the deadline, it’s hard to believe the Padres would trade him. They’d probably be better off hoping Ross – who’s making $9.63MM this year and will make one more trip through arbitration – rebuilds his value either through the end of the season or by the 2017 deadline. San Diego understandably wanted a large return for Ross last winter, but his shoulder troubles have likely killed the chances of that happening in the next couple months.