Baltimore Ravens head coach John Harbaugh has admitted that he is concerned by his side's off-field issues after Lorenzo Taliaferro became the fourth player arrested this year.

Taliaferro was charged with being drunk in public on Tuesday, and joins Ray Rice, Deonte Thompson and Jah Reid in having disciplinary issues in 2014.

"It's a privilege playing in this league," Harbaugh told The Baltimore Sun on Thursday.

"Character is very important to us - discipline is a way of life. I'm very disappointed in some of the things that have gone on."

The Ravens won the 2012 Super Bowl.