Wasn't that a concern when they drafted him? I mean, it's a concern with every pitcher, especially hard-throwing ones. I don't remember hearing anything specific about his motion that was a concern, though. He had to be shut down from pitching his senior season due to arm problems. https://www.tapinto.net/towns/west-essex/sections/sports/articles/paterson-s-nazier-mule-looks-forward-to-bright-baseball-future-after-being-drafted-by-chicago-cubs-89ff7112-fc55-42aa-a949-8df85016fd3f