Rizzo: Not impressed with Steven Shell
Acting general manager Mike Rizzo acknowledged on Tuesday that he wasn’t impressed with right-hander Steven Shell, who was designated for assignment on Sunday after posting a 5.40 ERA in four relief appearances.
“I didn’t like the mind-set on the mound and his preparation for the game. I didn’t like his whole aura on the mound,” Rizzo said “We talked to him all through spring.”
Last year, Shell had a solid rookie season in 2008, posting a 2.16 ERA in 39 relief appearances, but a few people in the organization believed it was a fluke. They felt Shell didn’t have the fastball to get hitters out consistently.

Could be correct, but is this to say he is impressed with Rivera?
Mike Rizzo is a great guy and he’s going to do a great job as gm, but as you said, Shell posted excellent numbers last year, which included batters hitting only .194 against him. Shell is a hard worker, well-liked by teammates, and will have lots more success in the future.