The Indians declined a $9 million option and allowed Sizemore to become a free agent less than three weeks ago.
Sizemore, 29, has generated interest from at least eight teams and appeared ready to let the market play out over the coming weeks. But the Indians moved to the front of the line Friday.
"The Indians came at us with an aggressive offer,'' agent Joe Urbon told ESPN.com's Jerry Crasnick. "Grady has always maintained that he would be interested in returning to Cleveland.''
On Saturday morning, Urbon emailed a note to reporters with an update on his discussions with Cleveland.
"We will continue to work through details with the Indians over the weekend. During that time we will have no further comment,'' he wrote.
Sizemore, who began his career with Montreal in 2000, came to Cleveland with Cliff Lee and Brandon Phillips in 2004 as part of a six-player trade that sent Bartolo Colon to the Expos. He emerged as a star at age 22 and made three straight All-Star teams from 2006 through 2008, but in recent years he's had trouble staying on the field because of injuries.
Sizemore hit .224 with 10 homers in 71 games this year, and the Indians recently declined his 2012 option and paid him a $500,000 buyout.
Since becoming a free agent, Sizemore has generated interest from the Philadelphia Phillies, Colorado Rockies, Boston Red Sox, Texas Rangers, Chicago Cubs, San Francisco Giants and New York Yankees -- teams that viewed him as an intriguing bounce-back candidate on a one-year deal. Those clubs either called Urbon to express interest in Sizemore or asked to check out his medical records as a prelude to contract talks.
Buster Olney is a senior writer for ESPN The Magazine. Jerry Crasnick is a senior writer for ESPN.com.