It's always a hot topic among Arizona Diamondbacks fans — and, truthfully, 29 other fanbases, as well. Fans are quick to express displeasure with certain players' playing time , or, often the lack thereof. Rookie infielder Jose Fernandez, with his .301/.337/.430 slash , has taken just one at-bat since the D-backs left Wrigley Field four days ago — a pinch-hit at-bat in Arizona's 1-0 loss to Paul Skenes and the Pittsburgh Pirates. But Fernandez is playing Thursday, against another tough arm in Mitch Keller. "He's a good player. He's still learning and emerging. I don't want to protect him, I want to expose him to some of the best pitching," manager Torey Lovullo said.…