The Vikings agreed to terms with nose tackle Linval Joseph on Tuesday, but it appears they're looking to add another defensive lineman.

Bears defensive tackle Henry Melton will visit the Vikings on Thursday, according to Melton played just three games last season before suffering a season-ending knee injury. He had reconstructive knee surgery in October and the Vikings will likely want to see if Melton has fully recovered from the operation.

He'll likely be a three-technique option for Zimmer along with defensive tackle Sharrif Floyd, who the Vikings drafted in the first round last year. Melton, 27, has recorded 15.5 career sacks in four seasons, including a career high seven sakcs in 2011.

Outside of Melton, it's been a quiet day so far for the Vikings. General manager Rick Spielman, head coach Mike Zimmer and offensive coordinator Norv Turner all were on hand at Alabama's Pro Day to watch quarterback AJ McCarron and linebacker C.J. Mosley, two possible draft picks in the first two rounds.