Jeremy Piven -- FORGIVING STEVE BARTMAN ... Could Save the Cubs

Chicago Cubs superfan Jeremy Piven tells TMZ Sports ... the time has come for all Cubs fans to FORGIVE Steve Bartman ... because it could help change the team's juju.

Of course, Bartman became persona non grata (to put it nicely) at Wrigley Field back in 2003 when he interfered with a catchable foul ball during Game 6 of the NLCS and got blamed for costing the team the series.

Bartman says he hasn't returned to Wrigley since the incident.

But over the weekend, Piven says Cubs Nation shouldn't just give him a pass ... but make him feel comfortable coming to games again ... even if that means giving the guy a hug.