Jim Harbaugh advised his players to be aware of their surroundings when off the field as the San Francisco 49ers broke minicamp.

"Beware with whom you associate," Harbaugh said of his message to players. "It's very important to know your surroundings. Friend or foe? There always seem to be a foe. Get in football position. See around corners, under doors, and anticipate. But mainly surround yourselves around good people."

Colin Kaepernick and Aldon Smith have had offseason issues.