Walker looked strong in his first bullpen session of camp Saturday, Greg Johns of MLB.com reports.
The veteran right-hander just returned to the organization where he got his start, and he's considered a legitimate candidate for the No. 5 starter job. While a bullpen session is essentially the most preliminary of tests for a pitcher coming back from a pair of injury-marred seasons, it certainly lends some reason for optimism as camp begins. Walker was limited to 14 innings across four appearances over the last two campaigns with the Diamondbacks due to shoulder problems and Tommy John surgery.