Head coach John Harbaugh explained Monroe's absence as a "front-office-type situation."
"My understanding right now is that teams are inquiring about Eugene," Harbaugh said after Tuesday's practice. "And when you're in that kind of a situation and there is a possibility of those kinds of things happening, you're pretty much obligated to pull back and not practice a guy."
Monroe hasn't practiced this offseason after undergoing season-ending shoulder surgery last season, but he announced a week ago that he was medically cleared to practice.
Monroe tweeted on Friday that the Ravens were distancing themselves from him and his cause. He has been campaigning vigorously for the NFL to take medical marijuana off its banned substances list.
If the Ravens trade or release Monroe, they would create $6.5 million in cap room and take on $2.2 million in dead money in 2016 and $4.4 million next year. Ronnie Stanley, the No. 6 overall pick in this year's draft, is working at Monroe's left tackle spot.
"That's where it's at right now," Harbaugh said. "It's in Ozzie's hands."