Parkinson was held out of practice Wednesday due to a biceps injury, John Boyle of the Seahawks' official site reports.
It's unclear when Parkinson hurt his biceps, as he logged his usual allotment of snaps in Sunday's loss to Baltimore. The 24-year-old has maintained a fairly even snap count with fellow tight ends Noah Fant and Will Dissly over the past four weeks, and Parkinson has paced the trio with six catches over that span. His status for Sunday's contest against Washington should become clearer as the practice week progresses.