Grant hasn't received an offer from the Green Bay Packers, with whom he spent the first five seasons of his career. He also visited the New England Patriots on April 20 and is believed to have received an offer from them, according to ESPN Milwaukee.
The Packers didn't pick a running back in last week's NFL draft, and if they want to keep Grant in their backfield rotation, they probably will have to make a decision soon.
Grant's 2010 season was cut short by a knee injury, and he rushed for 559 yards on 134 carries in 2011 while sharing time with James Starks in the backfield. If Grant were to sign with the Lions, he'd enter an unstable backfield that's currently counting on Jahvid Best to make a recovery from a head injury that shortened his 2011 season.