Irrational’s creative director Ken Levine has commented on the two departures:

"In a company of 200 people you're going to have turnover," he said.

"We never like to see a guy like Nate leave because he's been here for a long time but it's been 13 years and I think sometimes people want to spread their wings. I'm not going to stop people. We love Nate and I think we all remain friends. After 13 years he sort of finished his work on BioShock Infinite, as you will be able to tell when you see the game again… I think Nate's moving on to something else."

Much of the remaining team worked on the first BioShock were still with Irrational, said Levine.

“I don't think there's a single senior BioShock team member that isn't here, which I think is amazing and a testament to their commitment to the studio. And there are a ton of amazing people who weren't on BioShock 1 that are on BioShock Infinite."

Original story:

Two members of the BioShock Infinite development team have left Irrational Games, raising concerns about the state of the highly-anticipated title.

Art director Nate Wells, who was with the studio for 13 years and whose style shaped much of the original BioShock, confirmed his departure via now-deleted entries on his Twitter and LinkedIn profile.

His LinkedIn page briefly listed Naughty Dog among his employers in 2012, leading to speculation he had joined the Uncharted developer.

Now-former director of product development Tim Gerritsen’s LinkedIn profile lists Irrational as a past employer.

Before Irrational, Gerritsen was chairman and business director at Human Head Studios (Prey).

These are not the first setbacks BioShock Infinite has seen. In May, Irrational boss Ken Levine announced that the game’s launch would be delayed from October this year until February 2013.