Saints Execs love Spencer Rattler per ESPN’s Matt Miller

St. Widge said
The deep ball issues have nothing to do with lack of arm strength. They are caused by his lack of time practicing with the MASH unit of WRs that we put on the field when Rattler was playing. He had no time to get timing down with those guys because DA ran practices at half speed and they weren't even here during training camp.

You're absolutely right.

I'll add that lack of time to make his reads (even Peyton Manning was slow his rookie year) and having no pocket to step up in, both also contributed to his inability to make consistent long throws.