12:07pm: SI.com's Jon Heyman adds the Mariners and Rangers to the mix, saying Durbin is deciding between those two plus the previously reported Rays, Red Sox, and Phillies (Twitter link).
WEDNESDAY, 9:41am: Nick Cafardo of The Boston Globe says the Red Sox have not yet heard back from Durbin, and it appears that the Phillies and Rays are the front-runners at the moment (Twitter link).
TUESDAY, 7:11pm: Durbin would accept a minor league contract with the Phillies, reports Matt Gelb of the Philadelphia Inquirer, "if Durbin's hand is forced because there are no Major League offers on the table." A source tells Gelb that Durbin's agent, Dan Horwits, is negotiating with two teams about Major League contracts but no offers have been made. Gelb also hears that Durbin hopes to make his decision within the next two days.
4:39pm: The Red Sox are interested in Chad Durbin as a starter and have made him an offer, according to Peter Gammons of MLB Network (on Twitter). The Rays and Rangers also have some degree of interest in Durbin, according to Gammons.
One of the top remaining free agents, Durbin has drawn interest from Seattle since exchanging offers with the Phillies last month. It seems unlikely that Durbin will return to Philadelphia, but Gammons says he may head to Clearwater, where the Phillies train, Thursday. He could be intrigued by Boston's offer given his interest in playing for a contender.
The 33-year-old posted a 3.80 ERA with 8.3 K/9, 3.5 BB/9 and a 42.4% ground ball rate in 68 2/3 innings last year. Durbin has averaged 65 appearances and 75 innings in three seasons out of the Phillies' bullpen.