LAS VEGAS (KLAS) — With the Raiders searching for consistency on offense, tight end Darren Waller and wide receiver Hunter Renfrow are headed for injured reserve, the team said Thursday.

The moves mean Waller (hamstring) and Renfrow (rib, hamstring) will sit out at least the next four games.

Waller has missed the past three games with his injuries.

The Raiders did add two players to the roster, signing linebackers Curtis Bolton and Reggie Ragland. Both have seen action with other teams. Bolton played for Indianapolis, San Francisco and Detroit last season. Ragland has played six seasons with Kansas City, Detroit and the New York Giants.

Also on Thursday the Raiders placed linebacker Blake Martinez on the reserve/retired list.