According to this report by Jason La Canfora, recently released Browns linebacker D'Qwell Jackson has visits lined up with the Titans and Broncos. But in that same article, Jason La Canfora mentions that the Vikings are also reportedly interested in Jackson.
The Browns released Jackson right before he was set to earn a $4 Million roster bonus, and the 30-year old linebacker (who will turn 31 right at the start of the season) is now a free agent and ready to sign with any team. From the same article:
Several other teams are hoping to line up time with Jackson, and the Browns served him well by releasing him so soon before the March 11 start of free agency. Jackson is beloved by his teammates and a tackling machine. Some scouts believe he has slowed down, but, with so much interest, he could end up earning around the $8 million in total compensation he was set to get from Cleveland this season.
Pro Football Focus rated Jackson's 2013 season poorly, ranking 42nd out of 55 qualifying inside linebackers with an overall grade of -11.5. His poor play was mostly due to run stoppage, but he did reasonably well in coverage and as a pass rusher. The Vikings would do well to explore all options at linebacker with the recent release of Erin Henderson and either inexperienced or aging players as the only remaining options on the roster.