Jackson wasn't the only Eagles star caught off guard by the move.
"I heard the rumors, but I was surprised for sure," running back LeSean McCoy said, according to FOXSports.com. "I mean, he's probably one of our biggest playmakers that we had. He can make plays at any given time. He can control the game. He's probably the biggest deep threat in the NFL.
"To lose a guy like that is definitely tough. He'll definitely be missed. Obviously every move is made for a reason."
A CBS Philly report cited sources inside the Eagles' building saying that Jackson was a temperamental nuisance who clashed with Kelly's team-first aesthetic. McCoy is putting his faith in the Eagles' front-office officials.
"The guys upstairs made the decision for a reason," he said. "When you do things like that, you have backup plans in your mind. You don't let one of the top wide receivers go and then not have anything to back it up. I'm sure coach (Chip) Kelly and (general manager) Howie (Roseman), they'll be able to take care of it."
The Eagles undoubtedly have a plan. The question is whether they'll be able to come close to filling Jackson's substantial void in production. It's a tall challenge.