"He did a nice job," said Trembley of Hernandez. "We look forward to getting him back at some particular point in time. Koji's activated and starts [Thursday] and we expect a good game out of him."
Hernandez, who ranked second in the Triple-A International League in strikeouts at the time of his promotion, served notice that he may be ready to adjust to big league hitters. The right-hander went 1-1 with a 3.95 ERA in two starts and one relief appearance, and Trembley was impressed by his progress from Spring Training.
"I think he has cleaned up his delivery a lot," said Trembley, focusing on an area of improvement. "[Pitching coach Rick Kranitz] was very complimentary to him this afternoon and told him that he's very good out of the stretch. His delivery has gotten better out of the windup, his changeup has improved and I think he's a power-type pitcher that has a chance to have three average or above-average pitches. But he needs to go and pitch."
Hernandez pitched into the sixth inning of both of his starts, and he'll rejoin the Norfolk rotation on Saturday. The former 16th-round draftee has ignited discussions about whether he'll ultimately fit best as a starter or reliever, and Trembley said that's a decision that will be made in the future.
"For him right now, the best thing is for him to go to Triple-A and start," Trembley said. "I'm not saying that's where he'll be down the road, but I think right now he should go start. We'll see where our needs are and where his progress is at the next time around. I'm sure he'll be back here at some point in time before the season's over."
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.