I think those are two different topics, both of which are fair.
A player is going to have a hard time showing what he can do without some playing time to prove it. That's one topic.
The other?
The Cardinals are experiencing a run of players who have experienced trouble sustaining the success that brought them into the majors, and building off of it.
Examples include Harrison Bader, who has been up and down, Tommy Edman, who took a step back last season after an awesome rookie debut, and even Paul DeJong to some degree. Dylan Carlson will try to snap the streak.
The Cardinals have said they need to be sure they are giving opportunities to the right guys, but that doesn't eliminate the conversation about why some of the guys they are giving opportunities to have experienced plateaus in development.
Some of this, of course, has to do with expectations.
I think Cardinals fans have a bad habit of expecting every rookie to be a star.
That's just not how it works.
But the team has fed into this notion, especially when it is lacking in star power.
That's why an Arenado addition helps in so many ways. He takes some of the spotlight and pressure, and he is the kind of player who deserves both.