The Pirates shouldn't promote Gregory Polanco until the middle of next month, and they probably aren't going to. That's what I think, and you know, because I've said it about 80 times.
In the meantime, I've got another idea. The Pirates could promote Andrew Lambo to play right field against righties until Polanco is ready.
The Polanco issue is, of course, primarily about Polanco's talent, but it's also about Travis Snider and Jose Tabata not getting the job done. Even though Tabata has been part of the problem, though, we'll give him a pass and focus on Snider, since Snider, Lambo and Polanco are all lefties.
Snider has been, roughly, a replacement-level player this year. He projects to be slightly above replacement level the rest of the season. He's already in the arbitration process, and because his rising salary and Polanco's presence, it's highly unlikely he'll be back next season. He also now has, believe it or not, 1,420 career plate appearances.
Snider is still just 26 and a former top prospect. Maybe he'll be a late bloomer in the Brandon Moss mode. But I see no good reason to bet on that. There are few good reasons to continue giving Snider plate appearances for evaluative purposes, and even fewer good reasons to give him plate appearances because of the likelihood that he'll perform. His future with the Pirates is very limited, and if he can't perform at an adequate level right now, he's a good candidate to be replaced.
Some skepticism about Lambo certainly is warranted -- even in a breakout year in 2013, he struck out more than you'd like. He also has been trying to get through the high minors for longer than Abigail Breslin has been alive. And then there are his struggles in spring training this year. He wasn't a good Plan A for the Pirates at first base this year, which is one reason I liked the Ike Davis trade.
He is, however, a very interesting Plan B, and while the Pirates wait for Polanco, they need a Plan B in right field. Whatever problems Lambo had in March, it looks like he's addressed them. He's now hitting .354/.440/.557 in Indianapolis, with 11 doubles in 79 at bats. And if the right field tandem isn't performing, I see no reason not to give him a shot. He's not good enough for us to be concerned about his Super Two status, or about whether the Pirates are jerking him around. If he can help, he ought to come up and help, and if he plays well, the Pirates can carve out a bench role for him when Polanco comes up, or simply send him back to Indianapolis. (Obviously, Lambo should not affect the timing of Polanco's promotion, or prevent Polanco from receiving playing time.)
I haven't seen Lambo play in the last few weeks. Maybe there are still some exploitable holes in his game. If not, though, I think the Pirates should strongly consider promoting him and designating Snider for assignment. There is, at this point, reasonable evidence that Lambo might be helpful, and lots of evidence that Snider probably won't be.