You can get the full audio on Rick Stroud's Sports Day TB podcast. It's the sit down he did at the combine with the TB media.
It starts at 27:10. at the 42min mark is where he talks about Jameis and Desean.
https://soundcloud.com/sportsdaytb/lightning-win-franchise-best-10th-in-a-row-and-bruce-arians-on-desean-jackson-peyton-barber-more
Scott Reynolds: "In terms of Jameis inability of hitting the deep ball to Desean Jackson, is that just fundamentals? How do you coach a deep thrower?"
Arians: "It's part fundamentals, and it's part looking safeties off too long. Your release timing for Mike...then you try to have the same release for Desean, when Desean is 10 yards sprinting down the field. Now you're heaving it, you're not passing it. So it's just little things in getting it out of his hand faster."