Dobson is dealing with a hamstring injury, Darren Urban of the Cardinals' official site reports.
Prior to Friday's practice, head coach Bruce Arians relayed info on the health of two wideouts, stating John Brown is poised to miss a "couple days" due to a quad injury, while Dobson will be "out longer." The Cardinals will likely keep six wideouts on the 53-man roster this season, five of which are held down by Fitzgerald, Brown, J.J. Nelson, Jaron Brown and rookie Chad Williams. Consequently, Dobson is likely vying with the likes of Brittan Golden and Jeremy Ross for one spot. Any significant absence hurts Dobson's cause.