The agent addressed the team Thursday.
"It's just about being proactive," Edsall said.
He said the message was "how they have to be careful of who they're associating with."
The informal talk follows the disclosure by Yahoo! Sports earlier this week that a former Miami booster provided impermissible benefits to at least 72 athletes from 2002 through 2010. The booster, Nevin Shapiro, is in prison for his role in a Ponzi scheme.
Coaches use a variety of measures to try to keep players out of trouble. Edsall's predecessor, Ralph Friedgen, was known to dispatch assistants to monitor local bars. His coaches also conducted periodic evening dormitory checks.
Edsall said the timing of the FBI agent's talk wasn't related to the Miami situation.
"That was something I had planned … so they understand the position they're in," the coach said.
Miami is Maryland's opening opponent at Byrd Stadium on Sept. 5.
It's uncertain whether prominent Hurricanes players may be suspended because of interaction with Shapiro.
But Edsall said the Miami situation hasn't complicated his team's preparation.
"That's not even a concern of mine," he said. "We've just got to worry about Maryland."
Hustle and flow
Edsall expressed frustration after a morning practice in which he loudly criticized players for not hustling during a long field-goal drill.
"We just had some incidents," the coach said. "When I see something I don't like and I don't address it, then I'm cheating the kids."
Safety Matt Robinson (Atholton) said Edsall became upset when linemen appeared to jog downfield during a long field-goal simulation instead of sprinting down in coverage. The coach temporarily halted practice to make his point.
Asked if his concern was over that particular drill or practice issues in general, Edsall replied: "Both."
The coach, who in his first season with the Terps, said this is a critical part of training camp with the opener two weeks from Monday.
"This is where you find out about your team," he said.
Kicking it up a notch
Last season was a trying one for kicker Nick Ferrara, who lost his field-goal job to Travis Baltz.
Ferrara, now a junior, is intent on having a big season, and coaches say he is kicking with confidence.
"He's kicked the ball well," Edsall said.
Ferrara handled kickoffs last season while Baltz was used for field goals and extra points. Ferrara was the field-goal kicker as a freshman, converting 18 of 25 attempts.