Perriman fell on his knee after making a sideline catch and walked off the field with a trainer with about 15 minutes left in practice. He seemed to favor his right leg, but he went into the team facility on his own power.
"It's not serious. It's all sound," coach John Harbaugh said. "He'll be back as soon as his knee feels a little bit better. It could be as early as tomorrow or a couple of days at the most."
Per Harbaugh, this is probably nothing to worry about. Hopefully Perriman will be back on the field within a few days. He needs all the practice reps he can get as he tries to win the starting job opposite Steve Smith.