Earlier this week, the NFL threatened four players with suspensions if they didn't cooperate with the league's investigation into allegations that they all received performance-enhancing drugs from the Guyer Institute in Indiana.

Three of the players are currently on NFL rosters -- Steelers linebacker James Harrison and Packers linebackers Clay Matthews and Julius Peppers -- and Harrison said Tuesday that he was "definitely" prepared to sit over the NFL's interview demands.

But with little leverage, apparently all three players have decided to meet with the league, according to USA Today's Tom Pelissero.

The fourth player, Mike Neal, is currently a free agent. Pelissero reports that he has not agreed to be interviewed.

According to CBSSports.com NFL insider Jason La Canfora, the Harrison meeting will come on Aug. 28.