The Vikings agreed to trade for Miami deep threat Mike Wallace on Friday, the same day they were hosting former Tampa Bay defensive end Michael Johnson and searching for a new man in the middle.

Jasper Brinkley, the Vikings’ starting middle linebacker in 2014, agreed to terms with the Cowboys, according to a league source. Brinkley did a solid job against the run, finishing with 74 tackles. But because of his limitations in pass coverage, Brinkley played only 42.5 percent of the defensive snaps. The Vikings now must find a new middle linebacker, though chances are they already were looking for one, which is why Brinkley was allowed to walk.

Coach Mike Zimmer said that the free-agent class was underwhelming, but a few intriguing ones are out there. Rolando McClain remains unsigned, but he’s an enigma who un-retired and has past legal issues. Brandon Spikes is a two-down thumper like Brinkley, but he, too, has trouble keeping up in coverage. Mason Foster, Nate Irving and D.J. Williams also are unsigned.

The Vikings could opt to address middle linebacker in the draft — they have been eyeing prospects such as Denzel Perryman, Benardrick McKinney and Stephone Anthony — or give a longer look to Audie Cole, who opened eyes with 14 tackles in the season finale.

Ponder a Raider

Christian Ponder has found a new home — and the Vikings will visit him there in 2015. Ponder signed a one-year contract Friday with Oakland, a 2015 Vikings opponent. The offensive coordinator for the Raiders is Bill Musgrave, his former OC in Minnesota. The Raiders have a young starter in Derek Carr, who was drafted four picks after Teddy Bridgewater. The Vikings had no interest in re-signing Ponder, their 2011 first-round draft pick.