However, Jon Heyman of CBS Sports and MLB Network tweeted that Sanchez is still talking to other teams and the Tigers continue to be involved, according to Sanchez's agent, Gene Mato.
The Cubs would not comment on the reports, and sources told MLB.com on Thursday that no deal had been finalized with Sanchez.
Sanchez went 9-13 with a 3.86 ERA in 31 starts last season, which he began with the Marlins before a July 23 trade sent him to the Tigers. He then posted a 1.77 ERA in three postseason outings as Detroit advanced to the World Series.
A native of Venezuela, Sanchez will turn 29 in February and would figure to fit at the top of the Cubs' rotation, along with Matt Garza and Jeff Samardzija. The club already signed Scott Baker and Scott Feldman this offseason, and also has lefty Travis Wood.
The Tigers, who gave up highly touted pitching prospect Jacob Turner in a package for Sanchez and infielder Omar Infante, were thought to be one of the front-runners for his services.
Sanchez was signed by the Red Sox in 2001 and debuted with the Marlins in 2006, throwing a no-hitter that September. After some earlier injury problems, Sanchez has made 95 starts over the last three seasons, going 30-34 with a 3.70 ERA and averages of 8.1 strikeouts and 2.8 walks per nine innings.
Andrew Simon is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.