The Dallas Cowboys are switching from a 3-4 to Monte Kiffin's Tampa 2 scheme, and they'll be looking for the right personnel to help with the transition. Most people expect them to address this issue in the upcoming NFL draft.

SB Nation's Dan Kadar released his latest mock draft on Monday. In it, he has the Cowboys selecting Missouri DT Sheldon Richardson with the 18th overall pick:

The Cowboys would be fortunate to land a gap-splitting defensive tackle like Richardson with this pick. He's by far the best player available, though his attitude may rub some teams the wrong way. Moving to a 4-3 defense, Richardson is the exact kind of three-technique the Cowboys need.

Other possibilities: D.J. Fluker, Jonathan Cyprien

Dallas also needs help on the offensive line and safety, so guys like Flukeer and Cyprien would make a lot of sense at this spot.

Of course, with free agency just hours away, this mock draft is going to have a ton of changes over the next few days. Keep checking over at Mocking The Draft for updates.

More in the NFL:

• NFL mock draft: Changes on the eve of free agency

• Vikings trade Percy Harvin to Seahawks

• Ravens trade Anquan Boldin to 49ers

• Top 50 NFL free agents

• Crowdsourcing the Jets: When social media goes wrong

• Just how powerful is Roger Goodell?