Right now it looks like the Pirates have four pitchers in their rotation: Charlie Morton, Jeff Karstens, James McDonald and Kevin Correia. As you know, I have a preference about who the fifth should be, and we don't necessarily need another post about that person. But I would like to mention one of the arguments that has come up repeatedly in those threads, which is that the Pirates don't need another starter in part because they have guys like Brad Lincoln, Jeff Locke, Rudy Owens and Justin Wilson at the Class AAA level.
I'm not a big fan of these arguments, for two reasons. The first is that, even with the addition of a fifth guy (whether that's you-know-who or someone else) the Pirates already are giving one rotation spot to a replacement-level player in Correia, and another to Charlie Morton, who will have had an offseason surgery that has a long recovery time. There will be opportunities for the Class AAA guys to get starts.
Second, there's the separate question of whether giving starts to these guys is a prima facie good thing. Now clearly, if one of them starts performing really well in the International League for a couple months, the Pirates should clear space for them, and given the position the franchise is in, it would be ridiculous if they didn't. If Rudy Owens starts terrorizing Class AAA batters, we can all call for him to be promoted, and that includes me. Unfortunately, though, Owens had 71 strikeouts in 112.1 innings at Class AAA last year. He did pitch pretty well in July after struggling through May and June, but at this point, he has done little to show he would do anything but get pounded at the big-league level.
As for Wilson, it's not even clear that he's a starter at this point. He has control problems, so the Pirates tried him out of the 'pen at the end of the year. He continued to have control problems there, but he was throwing really hard, so the Pirates might continue using him as a reliever, where he has fantastic velocity for a lefty. Regardless, he had 94 strikeouts and 67 walks this year, which isn't the mark of a player who will be able to help as a big-league starter right away.
Locke pitched pretty well at both Class AA and AAA, but his stuff is unimpressive, and no one thinks he's likely to become more than maybe a middle-of-the-rotation guy in the long term. Also, he only has 28.1 Class AAA innings to his name, and he walked twice as many as he struck out in a small sample in the big leagues. More time at Class AAA might actually help him at this point, and there isn't yet a strong indication that he can step into the big-league rotation and succeed.
And then there's Lincoln. Of the four, Lincoln's performance record most strongly suggests he can survive in the big leagues. But he'll be 27 in May and has never had much success in the majors. He's been competent at Class AAA, but unspectacular. If he has to take some starts for the Pirates, that's fine with me, but he's certainly not good enough to consciously clear a spot for, or at least he hasn't been so far.
The Pirates will need depth this year. Lincoln will almost surely get his chances, and if Locke and Owens perform well, there will be space for them too. But these are not Grade-A prospects. In fact, in the cases of all except Lincoln, they haven't even shown they're ready for extended shots in the Pirates' rotation. Let them prove themselves first. Even with the addition of another pitcher, the Pirates' current rotation is weak enough that the Class AAA guys will get plenty of opportunities. If one of them emerges as a legitimate big-league starter, we'll know.