Kindle is the only unsigned pick from the 2010 draft.
The talks are focusing on a one-year contract. Kindle needs to rehab and recover from the fractured skull he suffered this offseason when he fell down two flights of stairs.
Last week, Kindle flunked a physical with the Ravens when doctors detected he struggled with his balance and reactions. No one knows when he will be able to return and, in the iterim, Kindle has returned to Dallas.
But if and when the two sides can work out a contract, Kindle could return to Baltimore, where the Ravens could oversee his rehab and try to help him recover in the hopes he can return to football.
Ravens coach John Harbaugh said Friday that it's doubtful that Kindle will play this season.
"He's got some serious issues that he's dealing with. I think the chances of him playing this year are slim," Harbaugh told reporters in Baltimore. "We'll be very, very careful. The doctors will be very careful. Sergio will be very careful with that type of an injury."
Adam Schefter is ESPN's NFL Insider.