Johnson is expected to be added to the major-league rotation to replace the injured Eduardo Rodriguez (knee), Evan Drellich of CSN New England reports.
The Red Sox can get by without a fifth starter until June 10, but all signs seem to be pointing toward Johnson claiming that spot when it comes around. Brandon Workman will fill the roster spot for now to provide some bullpen help, but Johnson will likely come up and replace him whenever Boston wants to get back to a five-man rotation. The 26-year-old southpaw holds a 2.82 ERA in seven starts with the PawSox, and he's been able to hold his own in the majors as well, as his 2.57 ERA in two big-league starts suggests.