"This is one step in that process to get him back to where he needs to be," McDermott told reporters.
Entering his fourth season in Buffalo, Watkins hasn't practiced since undergoing foot surgery in January.
"It's one day at a time at this point," McDermott said of Watkins, who is facing a pressure-packed, contract-year campaign in 2017.
After trading up to draft Watkins in the first-round of the 2014 draft, the Bills this offseason declined to pick up the wideout's fifth-year team option. That charts back to the long string of injuries that have forced Watkins to miss 11 games over the past two seasons.