How would you know if he is being a primadonna or not? IF he is not willing to go an extra out in the 8th or pitch multiple innings in big, late season games on occasion, then yes, I would have issues with a player’s wants coming before a team’s needs. What the team needs from Hader is really great innings like the ones he's giving them. As someone else pointed out, you don't know if he would be as effective overall if you're trying to squeeze 4-5 outs of him instead of 3, and you certainly wouldn't get as many outings out of him. Odd to assume that the role is a result of Hader being a primadonna rather than just perhaps the team recognizing that the current role has been working perfectly for both the team and Hader. Just want to make use of a weapon to its max, especially if, or rather when, we need him late in the season in the 8th.