Jose A. Ferrer is in his first spring training with the Seattle Mariners, and the feedback he's getting is basically: "You're a Mariners reliever, so act like one!"
They don't want Ferrer to be afraid of his secondary offerings. He was primarily a sinkerballer with the Washington Nationals, and reporting from Adam Jude of The Seattle Times posits that the Mariners want to see him mix in more sliders and changeups.
It's all there in this quote from pitching strategist Trent Blank:
"The present stuff is there. It’s a real fastball, a real sinker, obviously, that’s (his) carrying trait.