Here’s a quote you can read the whole article on the link.
No stunting Waller’s growth
The Raiders were content letting Jared Cook leave in free agency despite him being their best receiver last year. Darren Waller’s the main reason why, and he has shown playmaking ability during OTAs.
That was clear midway through Tuesday’s session when he hauled in an over-the-shoulder grab from Derek Carr. The Raiders quarterback quickly identified a favorable matchup outside with rookie cornerback Isaiah Johnson and threw a quick strike trusting Waller would win out. He did, bringing in one of a few nice plays made as the primary receiving tight end getting tons of first-team work that would’ve been unavailable with Cook around.