Kirkwood (hamstring) has been officially placed on injured reserve, Mike Triplett of ESPN.com reports.
Kirkwood injured his hamstring during pregame warmups prior to Sunday's loss to the Rams. The second year pass-catcher made an impression as an undrafted rookie last year but was still looking like just a depth receiver entering 2019. His absence figures to open up a bigger opportunity for Austin Carr, especially if Tre'Quan Smith (ankle) is forced to miss an extended period of time.