By shelling out big money for closer Joe Nathan and the negotiating rights to Yu Darvish, the Rangers have shown just how serious they are about improving their pitching staff.

And they might not be done yet, according to Fox Sports' Ken Rosenthal.

Rosenthal wrote Wednesday that the Rangers are still interested in A's closer Andrew Bailey, despite filing the winning bid for Darvish last week. Other teams in the mix for Bailey include the Red Sox and Rays.

By pursuing Darvish rather than a potential trade target like Matt Garza or Gio Gonzalez, the Rangers would be able to hold onto their most well-regarded prospects, giving them the ammunition necessary to pull off a deal with the A's.