I’ll grant that trying to answer this is unavoidably subjective. The Nationals just signed Brian Dozier, and a bone bruise might’ve clipped four wins from his WAR. The Braves are crossing their fingers for a healthy season from Josh Donaldson. Corey Seager is returning to the Dodgers after missing almost the whole year. The Cubs are looking for Yu Darvish to rebound. The Angels are looking for Zack Cozart to rebound. Dustin Pedroia should be coming back. Michael Pineda should be coming back. Buster Posey should be coming back. And so on and so forth. Baseball players get hurt. They try to put those injuries behind them. They try to get back to being what they were.
But as I think about this — certain recoveries are more predictable than others. Certain recovering players have bigger error bars than others. In a sense, the purpose behind this post is simply to remind you of the existence of Jimmy Nelson. But I think he really is the biggest injury wild card for the season ahead. The Brewers will play in a division with at least three and possibly five competitive teams. As of this moment, the Brewers are projected to have a below-average starting rotation. Jimmy Nelson might be a zero, as he was in 2018. Or he might be an ace, as he was in 2017. I don’t know which it’s going to be. The Brewers don’t, either.