I think Werth is going to be the guy. Don't know if it will be this week, but I expect heavy posturing toward Crawford and a substantial "take it or leave it" offer to Werth, which he will take with dollar signs in his eyes and Adrian Gonzalez as a new best friend.
Both of these guys, from all reports, are good to great clubhouse guys, team guys. If you're going to invest money, get guys you won't have to worry about in terms of effort, caring, maturity, etc.,
They don't like knuckleheads.
If they add Werth and Gonzalez, here are the two stat lines they can reasonably expect to add to the lineup to two of their open positions:
AVG season, last 3 years:
Gonzalez: 161 G, .285/..387/.523/.910, 36 HR, 106 RBI, 151 OPS+, 4.8 WAR
Werth: 150 G, .279/.376/.513/.889, 29 HR, 84 RBI, 132 OPS+, 4.2 WAR
FWIW, here are Beltre and Martinez's average seasons, last 3 years:
Beltre: 136 G, .286/.335/.471/.805, 20 HR, 74 RBI, 114 OPS+, 3.6 WAR
Martinez: 118 G, .298/.362/.462/.823, 15 HR, 74 RBI, 117 OPS+, 2.56 WAR
I think there's reason to believe that the addition of Werth and Gonzalez will be a significant net gain over Beltre and Martinez. They might also do better with draft picks as a bonus.