Lewis, who is recovering from a nagging calf injury to his left leg, missed his sixth consecutive practice Friday and was listed as doubtful for Sunday's game at Oakland.
The Jaguars (0-1) have four players listed as questionable, and coach Gus Bradley says receiver Mike Brown (back), guard Will Rackley (knee), cornerback Alan Ball (groin) and linebacker J.T. Thomas (hamstring) will be game-day decisions. All four sat out practice Friday.
Receiver Cecil Shorts III (groin), guard Uche Nwaneri (knee) and defensive tackle Roy Miller (knee) were limited in practice Friday and listed as probable.
The Jaguars already are down three starters, with receiver Justin Blackmon (suspended), quarterback Blaine Gabbert (hand) and cornerback Dwayne Gratz (ankle) out Sunday.