Mathis, 30, a former third-round pick, has played for four teams in his seven NFL seasons, including the Eagles (2011), Cincinnati Bengals (2008-10), Miami Dolphins (2008) and Carolina Panthers (2005-07).
He is viewed as one of the top three guards on the market along with Grubbs and Carl Nicks, the former Saints Pro Bowler whom the Tampa Bay Buccaneers made the NFL's highest-paid guard today.
Grubbs is rated higher than Mathis on most free-agent lists, but some prefer Mathis (here's one example). Given how Mathis bounced around the league before landing in Philadelphia and playing well last season, there should be concern about how he would translate if he left the Eagles for the Ravens. But at the very least, he would figure to be a solid replacement for Grubbs if that's how this situation plays out.
Winston, 28, started every game for the Texans from 2007 to 2011. He is viewed as the top right tackle on the market. He also played in a zone-blocking scheme in Houston similar to what the Ravens implemented this past season, which is a plus.