Gregg, 31, lost his job as the Cubs' closer in mid-August to Carlos Marmol.
Harden, who turned 28 on Monday, was classified as a Type B free agent, and the Cubs would've picked up a supplemental Draft pick if the right-hander was offered arbitration, declined, and then signed with another team.
He made 26 starts, his second-highest total since he made 31 in 2004 with Oakland. Harden did make 25 starts combined in 2008 with the Cubs and Athletics.
The Cubs think they have enough starting pitching for 2010 without Harden. The rotation now includes Carlos Zambrano, Ryan Dempster, Randy Wells and Ted Lilly, who had arthroscopic surgery on his left shoulder in early November. The fifth starter can come from a pool that includes Jeff Samardzija, Tom Gorzelanny and Sean Marshall, among others in the system.
If offered arbitration, and the players accepted, the Cubs would've been obligated for at least a one-year contract, and the players would've been in line for a raise. Gregg made $4.2 million in 2009, Harden $7 million and Johnson $3 million.
New Cubs chairman Tom Ricketts has said the payroll will go up only "slightly" in 2010, and the Cubs have to factor in raises to arbitration-eligible players such as Marmol, Marshall, Ryan Theriot, Mike Fontenot and Jeff Baker. Those players are affected by the non-tender deadline of Dec. 12, which is when teams must decide whether to tender a contract. Those players have less than six years of service time, and they are under team control for 2010.
Johnson and Fox were free agents, and neither was included on the Type A or B lists. Fox appeared in two games before being sidelined because of inflammation in his right elbow. Johnson, who turns 33 on Dec. 8, was limited to 65 games because of injuries.
The Cubs are in the market for a center fielder and could still re-sign Johnson, but if they did offer arbitration, they ran the risk of him getting a significant raise.