No visit has been scheduled with the Ravens, and no major contract has been offered yet, though. Guion is set to visit the Green Bay Packers on Sunday and Monday. The New England Patriots also are interested in the 6-foot-4, 303-pound Guion.
The Ravens are expected to monitor him in free agency.
Guion started 13 games for the Vikings last season and had 21 tackles, a sack and a forced fumble.
Two seasons ago, Guion had a career-high 31 tackles along with two sacks.
For his career, the former Florida State player has 89 tackles, five sacks and two forced fumbles.