Manager Kirk Gibson says Trumbo will get a second opinion from Dr. Michael Lee in Arizona before a timetable for his return is determined. An MRI Wednesday revealed the injury after an X-ray showed no structural damage.
The MRI also revealed some plantar fasciitis, which Trumbo had been dealing with since spring training. Trumbo wasn't sure how the stress fracture developed but thought he was overcompensating due to the plantar fasciitis.
Trumbo is hitting .210, though he was tied for the NL lead with seven home runs and was second with 19 RBIs before Wednesday's game against the Chicago Cubs.