Manager Torey Lovullo said Tuesday that Walker (oblique) is now asymptomatic and has begun hitting off a tee, Alex Weiner of ArizonaSports.com reports.
Walker had been limited to taking dry swings over the past several days while the team waited for the pain in his oblique to dissipate, but he'll now begin ramping up activities. It's still unclear how far away the 33-year-old is from a return to Arizona's lineup, but the acquisition of Josh Bell ahead of the trade deadline will allow the D-backs to approach Walker's rehab with less urgency.