With practically half of the 2019 MLB regular season complete, trade candidates have emerged. The Marlins are already out of playoff contention, which means their veterans will be drawing interest, such as Neil  Walker and Sergio  Romo, maybe Miguel  Rojas. Starlin  Castro has an intriguing track record, though he needs to get his act together fast. Wel be covering them plus other outside-the-box possibilities on Fish Stripes in the coming weeks.Adam  Conley might be gone by the July 31 deadline...but not via trade. Facing a 40-man roster crunch Cameron Maybin T-Shirt, the question is whether the Marlins will bother retaining the wiry left-hander down the stretch. He has been a liability over the past calendar year. Is there any hope for a turnaround?Entering June 25, 2018, Conley was rocking a spectacular 1.23 earned run average. He had rapidly established himself as one of Miami go-to, late-inning options. The former second-round draft pick seemingly found his niche at the highest level.Entering June 25, 2019, Conley is toxic. He has been failing to get outs (8.00 ERA), especially in situations where there no margin for error. His -1.27 Win Probability Added this season is worst among all qualified MLB left-handed relievers Justin Bour T-Shirt, according to FanGraphs.The most recent of the seven losses attributed to Conley this season happened last Wednesday in St. Louis. Paul  Goldschmidt, who been performing far below his usual standards with the Cardinals, took him deep 454 feet for a walk-off home run:Your browser does not support HTML5 video.He has not been on the mound since then.Conley didn even crack the 2018 Opening Day roster, pretty dispiriting for somebody entering their age-28 season https://www.marlinsteeshop.com/Odrisame … ne_T_shirt. An opportunity arose in mid-May when the Marlins needed a fresh arm Dillon Peters T-Shirt. However, groomed to be a starter throughout this pro career, he would have to settle for a relief role.The spike in Conley velocity in this new role was staggering. A four-seam fastball that sat in the low 90s the previous few seasons shot up to a 95.2 mph average. Nobody in Major League Baseball had a larger differential in their fastball velo from 2017 and 2018.Conley results came back down to Earth last July. Even so, a few days prior to the non-waiver deadline, Jeff Sullivan (formerly of FanGraphs) explained why contending teams should be interested:Conley throws one kind of fastball and one kind of changeup. In the past, it used to be that the changeup moved laterally a little more. Now, thanks to some kind of tweak, the average horizontal movements are virtually identical...The arm action is the same. The spin must look just about the same. Few pitchers are able to make their fastballs and changeups look so alike.What went wrong for Conley?     Steve Mitchell-USA TODAY Sports   Well, he began experimenting with a curveball this season, thinking it work be more effective than a slider. He was wrong. The new “weapon” was getting hard (.625 BA, 1.125 SLG, .622 xwOBA, 28.0 Whiff%) and has barely been used over the past two months.Also, his changeup isn fooling opponents anymore.2018 changeup results (209 pitches): .175 BA, .316 SLG, .224 xwOBA, 48.0 Whiff%2019 changeup results (95 pitches, including the Goldschmidt homer): .286 BA, .607 SLG, .378 xwOBA, 17.0 Whiff%The velocity gap between his fastball and offspeed has narrowed. At the time of Sullivan analysis, it was about 10 miles per hour; currently, it only 8.6 (95.8 fastball vs. 87.2 changeup).Moreover, Conley is struggling to “disguise” the changeup.2018: fastball averaged 16.9 inches of horizontal break with 2,261 RPM spin rate; changeup averaged 17.1 inches of horizontal break with 2,041 RPM spin rate2019: fastball averages 13.4 inches of horizontal break with 2,319 RPM spin rate; changeup averages 16.1 inches of horizontal break with 2,046 RPM spin rateIf major league hitters can identify what coming out of the pitcher hand and the pitch location isn precise, the quality of the stuff won matter.We have a rather large sample of ineffective Adam Conley, but it unclear how long his leash is to get straightened out. The Marlins don exactly have dynamic relievers forcing their way to The Show right now. That roster crunch is coming in 2020 when more of their young pitching prospects begin to specialize Jarlin Garcia T-Shirt.That being said, his current level of production is far below replacement level. During a season in which the Marlins wanted to show their fans that theye made incremental gains as a franchise, he has been holding them back.Over the past week while Conley has stayed away from game action, hopefully the coaching staff has been working with him to tweak some of the issues mentioned above.