Donatell, who participated in Seattle's rookie minicamp as a tryout player, is an undrafted rookie out of Western Kentucky, where last season he had 13 catches for 125 yards and two touchdowns. Prior to transferring to Western Kentucky, Donatell played at Wake Forest, beginning his college career at linebacker before moving to tight end in 2015. Williams, who spent part of last season on the Los Angeles Rams' practice squad, signed with the Seahawks last month.