The 6-foot-2, 296-pound Hovan took part in Thursday's morning practice session during the team's minicamp at Rams Park.
Hovan, 32, is entering his 11th NFL season. He spent the last five years with Tampa Bay but was released after the Bucs selected defensive tackles with their first two draft picks.
Hovan led all Tampa Bay defensive linemen three times in tackles. He started all 16 games last year and recorded 57 tackles, including 27 solo, along with a half-sack and 18 quarterback pressures.
He spent five seasons with the Vikings, who chose him in the first round of the draft out of Boston College.