From where I sit on my Ekornes stressless recliner he has bad hands, which manifest themselves in catching baseballs no matter how they originate.
Obviously catching a line drive, whether from a bat or an arm is way easier than catching balls bouncing, but not all throws to a first baseman are chest high on a line.
Maybe I'm over reacting, but he just looks to me like a miss waiting to happen.
Also maybe he can improve, but IMO that's unlikely. A guy with soft hands can learn to field grounders. A guy with a good but inaccurate arm can learn to throw. But bad hands...those are tough to fix.