Per Sullivan's MLB blog:
The Rangers are expecting pitcher Joe Nathan to decline his option for 2014 and become a free agent. A formal decision isn’t expected until after the World Series...
Nathan's contract for the Rangers is $9.5 million for 2014, but the closer will likely search for a multi-year contract. The 38-year-old relief pitcher posted a dominant season with 43 saves, fourth in the American League.
The former Minnesota Twins closer also posted a 73/22 K/BB ratio and a 1.39 ERA in 65 innings this season. Nathan signed a contract with the Rangers following Tommy John surgery and pitched in 129 innings overall with a 2.09 ERA.
The veteran closer has posted more than 30 saves every season since 2004, with the exception of 2011 when he suffered the injury that required Tommy John surgery.
As for options moving forward if they can't retain Nathan for the 2014 season, Sullivan notes that the Rangers are looking at other options for their closer with Joakim Soria, Neftali Feliz and possibly Tanner Scheppers on the short list.
There will likely be several suitors for the closer, but at 38, a multi-year contract for four or maybe even five years seems unattainable. Even at his age, Nathan remains one of the top relievers on the market this year given his stats and experience as a closer, which serves as a valuable asset to teams that could be in playoff contention.