INDIANAPOLIS -- Sen. Barack Obama will be back in Indianapolis this week after a last-minute schedule change to allow him to visit his gravely ill grandmother in Hawaii.

Campaign events originally planned for Madison, Wis., and Des Moines, Iowa, on Thursday will be replaced with a morning rally in Indianapolis, campaign officials said.

The rally will take place at the American Legion Mall downtown. Gates will open at 9 a.m., with Obama expected to speak at 11.

Obama drew an estimated 20,000 people to the same site for a speech the night before Indiana's May primary.

Thursday's event is free and tickets are not required, but supporters were encouraged to RSVP on the campaign's Web site.

The rally will be Obama's seventh Indiana appearance since mid-July -- including one earlier this month at the state fairgrounds -- as his campaign has made the strongest Democratic push in decades for the state's electoral votes.

Obama will leave after the rally to fly to Hawaii to be with his grandmother, Madelyn Payne Dunham. Campaign officials said Dunham, who helped raise Obama, was released from the hospital late last week, but her health had deteriorated to the point where her situation is very serious. She turns 86 on Sunday.

A poll by Public Policy Polling released on Tuesday showed Obama leading Republican Sen. John McCain by two points.

McCain's last visit to the state was July 1. McCain running mate Gov. Sarah Palin drew some 20,000 people to a rally in Noblesville last week.