A sequel to Naughty Dog's acclaimed action-survival game The Last of Us may be in the works, according to the resume of former Naughty Dog lead character artist Michael Knowland. According to Knowland's LinkedIn profile, Naughty Dog had produced prototype designs for use in The Last of Us 2 earlier this year.

Knowland had joined Naughty Dog in October 2011 and worked on The Last of Us as well as Uncharted 4: A Thief's End. At present, he is a senior character artist at Avalanche Studios and is working on Just Cause 3.

Knowland left Naughty Dog in April this year. His departure followed on from a number of high-ranking staff who left the studio, including Uncharted 4 director Justin Richmond, writer Amy Hennig, lead artist Nate Wells, and actor Todd Stashwick.

The Last of Us creative director Neil Druckmann said in a Reddit AMA last February that there was a "50/50" possibility of a sequel. Naughty Dog has since confirmed it is working on two new "brand-new experiences" one of which is Uncharted 4: A Thief's End, due to launch sometime next year.