Max Kepler and Jorge Polanco are the most recent examples of premature hype of young players based on some success in a limited number of at bats at the major league level. Last season started with Vargas and Santana inked into the lineup, this season it was Sano and Rosario. Before that it was Oswaldo Arcia. In all of these cases, stories seemed to anticipate improvement the second year while the players couldn't even carry over into the following year their initial success.
The reality is that players are often called up because they are hot at AAA and that sometimes carries over to the big leagues. Then the scouts do their work, major league pitchers are able to use the holes in their game and they crash back to earth. That is why Tom Kelly used to suggest you didn't really know what you had until 1000 at bats. Kepler looks like he is a winner and Polanco has been solid in a series of appearances. But, just as patience is often required for young players to establish themselves, even more patience is required before forming a firm opinion about players who have initial success.
There is a larger problem that the new focus on statistics has created. That is that during the season players, and teams, numbers are heavily weighted to early performance. Last year the Twins were a sub-500 team for the last four months of the season, but their hot May masked that reality. The same thing happens with individual players. They start out cold and it looks like they are having a terrible year. Or, especially with young players, they have a hot start and it masks their poor to mediocre performance for a long time.
Right now Kepler, Rosario and Polanco are hot. Rosario's resurgence after returning from Rochester is particularly encouraging. But we need to have some patience before we start talking about roster positions for the future. Just as we need to be patient with talented players who struggle initially. For the last month the Twins have looked like they will be contenders next year. But the reality of that depends on those young players continuing to show they are ready for the big leagues. Chances are some will and some won't.