Waller strained the inner side of the ankle and heel during practice Friday, when he was tripped by a teammate, according to a source who saw the play.
Waller's absence is a setback to a Raiders offense that rallied around interim head coach Rich Bisaccia during his NFL coaching debut last Sunday in a 34-24 win over the Broncos in Denver.
Without Waller, the Raiders will have to lean more on backup tight end Foster Moreau, who has four receptions for 53 yards and a touchdown this season.
The Raiders think Moreau can be effective, but Waller has emerged as one of the NFL's top offensive threats, a player whom former Raiders coach Jon Gruden called "the best player I've ever coached" earlier this year.
Waller, 29, has a team-leading 33 receptions for 378 yards and two touchdowns in six games this season, his fourth with the Raiders. He set a Raiders single-season franchise record last season with 107 catches.