Vikings' Antone Exum has matured into a viable starter at safety

Vikings rookie safety Antone Exum adjusts his helmet May 16, 2014, during rookie minicamp at Winter Park in Eden Prairie. (Photo by Hannah Foslien/Getty Images)Aug 2:

MANKATO, Minn.-- Antone Exum's confidence long has been evident. While at Virginia Tech, he recorded a rap song with the verse, "I'm the best corner in the country and you know it.''

Exum is now a safety, having been moved from cornerback last year as a Vikings rookie. As for his confidence, he realizes he perhaps has needed to tone things down a bit.

When Minnesota coach Mike Zimmer recently was asked about Exum, he said he has improved as a player and with his maturity. He said he needed to have several talks with Exum when he…