In eight spring innings, Watson has allowed six earned runs, two home runs, and has just two strikeouts. It should be noted that he has only walked one batter, which you could take as a good sign. Moskos on the other hand has allowed just one earned run in those same eight innings. He has seven strikeouts but has walked five.
You certainly don't want a guy coming in from the bullpen who is going to walk batters. Either of these guys is probably going to be mainly used as a situational pitcher. They'll come in to get one or two batters out, and you can't afford walks when you're doing that. For their minor league careers, Moskos has 3.7 BB/9 while Watson has 2.1. That, plus Watson's 2011 success and upside would give Watson the spot in my mind, but I'm not sure it's that simple right now.
Let's look at the pitch f/x for these two southpaws.
| Pitch | Selection | Velocity | V-Break | H-Break | Strike% | Whiff% |
| FB | 77.7% | 91.1 | 7.59 | 10.78 | 66.2% | 17.2% |
| SL | 9.3% | 84.1 | 3.71 | 2.38 | 67.2% | 17.2% |
| CH | 7.4% | 84.4 | 5.53 | 12.21 | 52.2% | 4.3 |
| Pitch | Selection | Velocity | V-Break | H-Break | Strike% | Whiff% |
| 2sFB | 37.2% | 91.3 | 5.65 | 9.22 | 60.3% | 8.1% |
| 4sFB | 28.1% | 92.3 | 7.93 | 4.84 | 65.0% | 4.9% |
| SL | 26.5% | 83.1 | 0.11 | 0.93 | 68.0% | 18.6% |
| CH | 7.7% | 85.2 | 6.05 | 8.04 | 53.6% | 10.7% |
These two guys are pretty similar with their velocities. Watson has a bit more movement on his pitches and he gets more whiffs with the fastball, which is the main pitch a lefty reliever needs. Moskos has put a lot of time into improving his breaking ball this offseason, so I could see his whiff rate on the slider improve (it's already pretty solid), and I wouldn't be surprised to see him incorporate some curveballs this year.
From purely stuff, Watson has a slight edge. It's not huge, and you could probably justify taking either of these guys to the Majors. You can't take them both, so you have to pick one. You have very small Major League samples from both guys (Moskos threw 24.1 innings last year and gave up eight runs while striking out just 4.1 batters per nine), so you can't go off of statistics here. I think you have to take the guy with more upside and better stuff (those two go hand-in-hand really), and that guy is Watson.
The Pirates could definitely have something in Moskos, but for right now I think he needs to head back to Indianapolis. Spring training statistics mean nothing, and the fact that Tony Watson might not make the team because of eight March innings seems a bit ridiculous to me.