Boxberger (back), who is expected to be activated Friday from the disabled list, gave up an earned run on four walks in two-thirds of an inning in Triple-A Durham's win over Norfolk on Wednesday.
Boxberger uncharacteristically had trouble finding the plate after having issued only a pair of free passes in the six innings he'd pitched during his rehab prior to Wednesday's outing. The 29-year-old threw a total of 31 pitches while working less than a full inning for the first time in his minor-league appearances, but he remains on track for his planned Friday activation.