Has Rusney Castillo played his last game in Pawtucket?

The Red Sox seem to finally be ready to make the call: it's time for Rusney Castillo to play in Boston. Speaking with the media ahead of Tuesday night's game against the Rangers, John Farrell more-or-less confirmed it's not a matter of weeks, but days, only opening the question to "whether or not [the Red Sox] allow him to get a game under his belt at Pawtucket" before they pull the trigger.

In fact, the way he says it, it sounds like the only reason Castillo didn't join the team in Fenway Tuesday night was because Castillo was busy dealing with more important things, specifically the birth of his first child. Castillo was absent from both Monday and Tuesday's Pawtucket games to be with his wife, but should be ready to return to action soon.

That leaves two questions. First is the one mentioned by Farrell of whether or not to get Castillo a game in Pawtucket to shake off a few day's rust before calling him up.

The second: who does he replace, and where does he play?

The obvious answer on the 25-man roster right now is, sadly, Daniel Nava. He's just about the easiest guy to root for on the team, and over the past few years has done more than anyone ever expected him to. But through 63 plate appearances, he's currently the worst of the team's underperforming players, hitting .151/.258/.170, and with the team as a whole struggling against lefties, his left-handed bat is not currently a priority.

If Mike Napoli hadn't gone deep on Tuesday, there's a very real possibility that's where Castillo would be finding most of his playing time. Not at first, mind, but in left, with Hanley Ramirez, who has been atrocious in the outfield, making the move back into the infield. But Napoli's homer is perhaps just enough a sign of life to keep him in the starting lineup for another week or so when you consider what a productive Napoli could bring to the team.

That would leave Castillo finding a little bit of playing time everywhere, most likely. Right field is no longer a given since Shane Victorino is hitting .353/.450/.588 since his return from the disabled list, and far better than that if you just go back through his last five appearances. Somehow, despite his terrible start, his season OBP is now up around .350. He'll probably still see mostly left-handed pitchers, which opens some opportunities up for Castillo there, but he'll likely have to pick up some other at bats in center or left, perhaps sometimes moving Hanley Ramirez to DH or, if Napoli struggles, even first base. Castillo does have some infield experience, but it's hard to imagine the Sox going on that particular adventure.

All this would mean that Brock Holt  will find himself with far fewer opportunities, but he really hasn't been making the most of those to in May to begin with. He's 7-for-40 with a .567 OPS in his last 45 trips to the plate.

Wherever Castillo plays, though, the Red Sox seem to know they need him. It's not clear right now whether first base, or half of right field, or all of right field is the problem spot in the lineup. But there's no doubt that it's an offense that could use some help, and that Castillo is their best hope to provide it just that.