EXCLUSIVE: Titus Welliver has been forced to leave the TNT drama pilot The Last Ship because of a family health emergency. The network would not elaborate, but Welliver’s wife has been ill.

In his first pilot since Chuck, NBC spy series’ co-star Adam Baldwin has been tapped to replace Welliver in Last Ship, executive produced by Michael Bay. Jonathan Mostow is set to direct the pilot written by Hank Steinberg and Steven Kane. Based on the novel by William Brinkley, The Last Ship centers on the crew of a naval destroyer who, after a global catastrophe decimates the Earth’s population, are forced to confront the reality of their new existence in a world where they are among the only survivors. Baldwin will play Mike Slattery, second in command to Captain Tom Chandler (Eric Dane) onboard the USS Nathan James. He’s a fair man who cares deeply for his family. He and Tom clash at times over the best course of action. Baldwin, repped by A Management and APA, recently did an arc on NBC’s Law & Order: SVU and appeared on TNT’s drama Leverage.

As for Welliver, given the circumstances, I hear TNT brass may find another role for him on Last Ship if it goes to series.