Believed to have high-ankle sprain

Brown received a preliminary diagnosis of a right high-ankle sprain after exiting Wednesday's 13-10 loss to the Seahawks, Ian Rapoport and Mike Garafolo of NFL Network report.

In his Patriots debut, Brown tallied three receptions for 26 yards on four targets before departing in the third quarter with the injury, which occurred when a Seahawks defender landed on his ankle. Though X-rays on his ankle returned negative, Brown will be sent in for an MRI on Thursday before the Patriots establish a timeline for his return. High-ankle sprains typically result in multi-week absences, so if the MRI confirms the preliminary diagnosis, Brown would face an uphill battle to suit up in the Patriots' next game Sept. 20 versus the Steelers.