Two more senior developers have left Irrational Games for pastures new.

The LinkedIn profiles of combat design director, Clint Bundrick, and AI lead, Don Norbury, show that both have moved on to take up roles at Microsoft. The changed roles were spotted on Twitter by Superannuation.

There have been several changes to the BioShock Infinite development team in recent months. A number of senior staff departed in August including Nate Wells (art director), Jeff McGann (design lead), Tim Gerritsen (director of product development) and Kenneth Strickland (principal systems designer). Nate Wells left for Naughty Dog to work on The Last of Us.

BioShock Infinite was originally due out on 16 October, but in May it was pushed back to February 2013. Ken Levine, the game’s creative director, said the team needed extra time to make specific tweaks that would make it “even more extraordinary”.

Infinite was absent during the conference season. However, a new trailer is due out next week with a countdown available on the official BioShock Facebook page.