Looking the the last RB's to win MVP, it seemingly rules out Gurley.
2012=Peterson, tops 2,000 yards rushing at 6 yards per carry, and leads the league by almost 500 yards, while almost single handedly willing the Vikings to the playoffs.
2006=Tomlinson, sets single season TD record and won the rushing title for a team that earned the #1 seed.
2005=Alexander, sets single season TD record, and won rushing title for a team that went to the Super Bowl. Also was a down year for QB's.
2000=Faulk, sets single season TD record, and was 2nd in yards from scrimmage, while missing 2 full games, and parts of others. Award probably goes to Warner if he hadn't missed 5 games.
1998=Davis, has 2,000 yards rushing and 23 TD's(record was 25 at the time) also was key player of Super Bowl Champs.
1997=Sanders,(co-MVP with Favre) had 2,000 yards rushing at over 6 yards per carry. Also was a bit of a lifetime achievement MVP, as I think another player with the same year doesn't get co-billing with Favre.
1993=Smith, won the rushing title despite sitting out essentially 3 games. Was key player for Super Bowl Champs.
1991=Thomas, lead the league in yards from scrimmage for a team that went to the Super Bowl.
The pattern seems to be, either have a historic season, or be the key player on a juggernaut team, and the latter seems to have been more of a 90's thing. Gurley didn't have a historic season, nor were the Rams a juggernaut team.