Changes are afoot at Call of Duty developer Infinity Ward.

Veteran producer Mark Rubin, who had been with the studio since 2005, has left. Meanwhile, Todd Alderman–who worked on the original Call of Duty and the influential 2007 shooter Modern Warfare–has returned to Infinity Ward as its multiplayer project director.

Mark Rubin

The personnel changes were revealed Monday as part of a Polygon report.

Rubin left Infinity Ward earlier this year, though no further details about his departure or what he might be doing next are available.

The report doesn’t name a replacement for Rubin, but does mention that Infinity Ward has made a number of key hires in recent months.

These include former Naughty Dog developers Taylor Kurosaki (narrative desgin lead) and Jacob Minkoff (lead game designer), as well as Michal Drobot (principal rendering engineer), who most recently worked at Ubisoft on Far Cry 4.

As for Alderman, he worked at Infinity Ward from 2002-2010, leaving that year in the wake of lawsuits regarding the controversial firing of co-founders Jason West and Vince Zampella. Alderman was one of the members in the “Infinity Ward Employee Group” that took Activision to court in 2010, seeking money for unpaid bonuses and more.

Aldermann, along with other former Infinity Ward staffers, later followed West and Zampella to their new studio, Respawn Entertainment, which went on to make Titanfall. He spent two-and-a-half years at Respawn before moving on, ultimately joining League of Legends developer Riot Games in April 2014.

The staffing changes at Infinity Ward come as the Call of Duty series transitions to a three-studio, three-year development cycle. The first game released on this schedule was last year’s Call of Duty: Advanced Warfare. The next is this year’s untitled game from Call of Duty: Black Ops creator Treyarch.

Assuming past patterns hold, Infinity Ward will be the main developer for a new Call of Duty game in 2016. Infinity Ward’s most recent game was 2013’s Call of Duty: Ghosts.