I dont think he really has stepped up. If anything hes taken a step back from how he was playing last season. The offense has been the main reason for the run the last 3 weeks.
He never played consistently last season so it's really tough to compare the two. Guys come up and have a solid game running on adrenaline, but it's almost always a flash in the pan. You can't get too up or down on a guy based on what he does on a random call up.
And I'm not going to suggest that Mrazek has been good the last four games because he hasn't, but I'm not going to hold it against him. He shouldn't be here right now. He should be in the AHL. But as said, I think it's good that he's getting this experience because it's going to push him all the harder.
Next year he's likely going to come in and play backup, and he'll get a lot of opportunities to prove himself. If he keeps growing and keeps pushing and cleans up some of the problem areas in his game, he'll do well in that role. He's got the skill set and potential to go toe and toe with Howard in the next couple years. A rough stretch on this extended call up is not going to change my mind about that.