Excellent question. I wish I had an excellent, surefire iron-clad answer. But there isn't one. I get completely why fans would be frustrated. They're told that Nogowski's spring performance was so strong that the Cardinals couldn't ignore him. Then they're also told that a veteran who struggled all spring -- well, those numbers don't matter. Perhaps we can borrow from the Cardinals' spring to explore this. At one point in spring, Nolan Arenado went zero-for-17. Was there a lot of angst in Cardinal Nation? Did anyone even notice? Or was it because he has a track record, and he was possibly working on things, and it really didn't show up because it wasn't like he was striking out a bunch -- that no one really got anxious about it. Arenado would be there at the end. He homered. He's on the plane. Away he goes.
It's best to thing of spring training performances then in what the individual has to accomplish -- and the style of player that individual is. There are some pitchers who will take a bruising in spring training because they need to get their sinker in shape, or they have to work and work and work on the changeup so that it gets battered in March but is there in April. Let's not fixate on those pitchers' ERAs, instead let's see how many innings they're logging, how much they're around the zone, how they're avoiding walks, etc. Check the velocity.
Spring training is less about the box score than it is about the numbers beyond the box score.
Nogowski had a lot of RBIs. But what got him on the team wasn't that. It was that he didn't strike out much, he hit high velocity pitches, he made contact, hard contact, a lot. Nogowski had results that the team could trumpet, but he also had all the other things that the team insists they were getting from some veterans. Nogowski had the exit velo that Carpenter had. That one game that Nogowski hit a home run, Carpenter had a ball he hit harder and farther -- for an out.
That's the way to look at spring right there -- process, not outcome. And do so by the individual. A player like Arenado is gearing up for the season, and can set a pace for the long haul. A player like Nogowski -- this is his season, his chance to make the team, he's working on producing now to get that chance to be part of something, so if he's a little head and has more production it's because he needs it to be on the team. The team just needs the other players, the veterans to be ready. They don't need to dazzle in spring.