The 5-foot-7, 22-year-old seems rather fearless on the mound, Ross said.
"He's doing exactly what he needs to do [as a rookie]," Ross said. "Go after them, do what you have to do and make it easy, don't try to make it too complicated."
Manager Ron Washington has been impressed with Ortiz's demeanor as well.
"He gets outs and he gets them quick," Washington said. "He acts like he has no pulse, really."
Washington wants to avoid overusing Ortiz, though.
"By the time Robbie got to the All-Star break [last season], he was blown out," Washington said. "We've got to try to monitor it [with Ortiz]."
Dave Sessions is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.