Shanahan, 62, did not coach this past season after he was fired by the Redskins in December 2013. In four seasons, he went 24-40 and appeared in just one playoff game.
Shanahan came to Washington after 14 years with the Denver Broncos, where he won two Super Bowls, made seven postseasons and went 138-86 from 1995-2008.
The 49ers' job became open when the team agreed to part ways with Jim Harbaugh last week. Shanahan's name was quickly connected to the opening, and it's believed that Shanahan could be interested in a return to coaching.
Shanahan's son, Kyle, who is the Cleveland Browns' offensive coordinator, has also been linked to the 49ers' opening. Broncos offensive coordinator Adam Gase was also expected to interview with the 49ers in Denver this weekend. Former New York Jets coach Rex Ryan will reportedly interview with the 49ers on Sunday, as well.
San Francisco's defensive coordinator, Vic Fangio, and Seattle Seahawks defensive coordinator Dan Quinn have also been linked to the opening.
- Mike Fiammetta