The Vikings could make yet another free-agency splash on defense, and it would fill big a need.

Unrestricted free-agent cornerback Captain Munnerlyn met with the Vikings on Wednesday night, according to an NFL source. He's expected to meet with the team again Thursday.

The Vikings have been actively seeking to add a cornerback this offseason. They made contact with cornerback Alterraun Verner's representation during the three-day negotiating window, but he signed with the Buccaneers on Tuesday.

Munnerlyn, 25, was a seventh-round selection for the Panthers in 2009 and spent all five NFL seasons in Carolina. The 5-9, 195-pound nickelback has returned five of his seven career interceptions for touchdowns. Munnerlyn had career highs in tackles (74), sacks (3 ½) and tied a career high in pass deflections (12) last season.

Munnerlyn has missed only three games in his career. The Vikings pass defense, which ranked 31st last season, allowing 287.4 yards per game, lacked depth at cornerback and dealt with a number of injuries. Josh Robinson, who has primarily played outside cornerback, shifted to nickel back at times last season before suffering a season-ending fractured sternum.

Xavier Rhodes played well as a rookie but battled through ankle and knee injuries. Chris Cook missed four games last season because of injuries and was inconsistent on the field.

The Vikings already have addressed their three biggest needs in free agency. They re-signed quarterback Matt Cassel and defensive end Everson Griffen and signed former Giants nose tackle Linval Joseph this week.

More help on D-line?

The Vikings might be in the market for another defensive tackle after signing Joseph. Bears defensive tackle Henry Melton will visit the Vikings on Thursday, according to NFL.com.

The unrestricted free agent played just three games last season because of a torn ACL in his left knee. He had reconstructive knee surgery in October and the Vikings likely will bring him in to see if his knee has fully recovered. Melton, 27, also spent his rookie year on injured reserve in 2009 because of an ankle injury.

Melton, who is listed at 6-3 and 295 pounds, could be a three-technique option for Zimmer right next to Joseph. The team already has a three-technique tackle on the roster in Sharrif Floyd, drafted in the first round last year.

Melton, who was selected in the fourth round by the Bears, has recorded 15 ½ career sacks in four years with Chicago, including seven in 2011 and six in 2012. He had a career-high 44 tackles and two forced fumbles in 2012.

At the moment, the Vikings are thin at defensive tackle outside of Joseph and Floyd. The only other defensive tackles on the roster are Chase Baker and Kheeston Randall.