ENGLEWOOD, Colo. (AP) — Wes Welker has passed concussion protocol and could be back on the field as soon as Sunday if the NFL signs off on a new drug policy approved by the players’ union.

Representatives of the NFL Players Association approved the comprehensive new policy Friday that includes implementation of testing for HGH and an increase in the threshold for testing positive for marijuana.

Welker was suspended four games for amphetamine use in the offseason, but punishment for that is being switched from the performance enhancers policy to the substance abuse program — except for in-season violations.

If the league approves the agreement, the Broncos’ slot receiver could be eligible to play when the Kansas City Chiefs visit Denver on Sunday.