Red Sox prospects daily: Rusney Castillo is struggling and Shane Victorino is back

Triple-A Pawtucket: Rusney Castillo, RF

When Rusney Castillo returned from the disabled list in late-April, there was the possibility that he would return to tearing up the opposition as he had done in his previous brief time in the minors and majors. That would, in turn, have put additional pressure on Shane Victorino to produce once he returned from his own DL stint. Instead, Castillo has mostly floundered, not even reaching base until his third game back and failing to register a hit until his fourth.

He's looked a little better of late now that he's gotten some swings in -- this is basically an unofficial rehab assignment for him, so seeing some struggles immediately wasn't surprising. The power still hasn't returned, but it is comforting to see Castillo drawing walks (three in his last five games) and mostly putting the ball in play. Even if Castillo's power doesn't come all the way back soon, if Victorino continues to disappoint, Rusney might get the call anyway so long as he looks comfortable at the plate. Shanf's days as an every day player look like they could be over, as his body just doesn't have a full season in it right now, and he might better serve the team in a bench role. With Allen Craig now optioned to Pawtucket in order to play every day, the space is certainly available in Boston.

That might mean Jackie Bradley Jr. has to be sent back down to Pawtucket, but given the questions about Castillo's health at this early stage in his career, having that kind of depth around just a short drive away isn't the worst thing. There might come a point where the Sox cut bait with Victorino entirely, but it probably isn't anytime soon until they know Castillo is absolutely ready and reliable.

Triple-A Pawtucket: Heath Hembree, RHP

Hembree was demolished in his one major-league appearance this year, allowing six runs in 1-1/3 innings, but it doesn't say a whole lot about him in the long run. No, Hembree isn't going to be a dominating force in Boston's bullpen, not at any point, but he's also not going to give up six hits in an inning-plus each time he's out there. It would have been a more standard disaster appearance if it weren't his only one of the season, but since it was, we have to stare at his 40.50 ERA until he gets another shot.

He's done well for Pawtucket, missing bats and finding the strike zone often enough to produce six times as many strikeouts as walks. He's still a viable option for bullpen depth, in the same mold right now as Tommy Layne and previously Alex Wilson, in terms of being someone the Sox can call up to soak up innings when they need to. He might never have a key, high-leverage role with the Sox, but someone who can reliably get outs and throw innings when the bullpen needs a dose of that can matter, and while his one appearance this year didn't show it, Hembree is that kind of pitcher.

High-A Salem: Daniel McGrath, LHP

Daniel McGrath didn't have the most outstanding season for Low-A Greenville a year ago, producing a 4.08 ERA over 19 starts and 97 innings while striking out just 1.6 times as many batters as he walked. The ERA is better this time around for the start of the Australian's Salem career, but the K/BB is even worse despite an increase in strikeouts. At some point, when McGrath starts to face hitters who can reliably and consistently earn hits off of him, things are going to get ugly.

McGrath might have some time before that occurs, of course: he just got to Salem to begin this year, and he's only 20 years old. Right now, the focus is on trying to learn to throw strikes consistently: he seems to have the quality strike portion of things down, given the low hit rates and the lack of homers, but he needs to be able to throw them more often. You know: on command. A few more grounders wouldn't hurt, either, as McGrath is one of the more fly ball-oriented pitchers in the whole system, but maybe one thing at a time for the 20-year-old lefty.

Low-A Greenville: Chandler Shepherd, RHP

Chandler Shepherd -- whom you might also have seen referred to as "James" Shepherd at some point -- is a reliever for the Drive, who is pitching multi-inning appearances. He was a potential top-100 pick in the 2014 draft according to Sox Prospects, but he fell all the way to the 13th round of the draft and into the Red Sox' hands instead. These things don't just happen, so don't automatically assume that Boston drafted a third-round talent 10 rounds later, but if he can rediscover what made him potentially intriguing, then there could be something pretty good here.

Shepherd is 22, and won't be 23 until the season is basically over. He pitched well for short-season Lowell after signing, with over nine strikeouts per nine and well over four times as many punch outs as free passes, and has improved in both of those areas to begin 2015. As he's already in relief, you don't need to guess to wonder if that's where the Red Sox envision him being.

There isn't one dominating pitch or anything, but instead a couple of potential average ones in his curve and change-up, and a fastball he can reliably throw for strikes. He's the kind of arm who could end up going nowhere because of health or because that second or third pitch never quite develops as hoped, but might also rocket through the system until he finds more of a challenge, should he continue on as he's been.