The Mercedes AMG Formula One team on Tuesday confirmed that its Technical Director Paddy Lowe has stepped down.

Lowe is currently on garden leave but is expected to join another team. It’s rumored he may end up at Williams, which is using Mercedes power units.  

“I have had a fantastically successful and enjoyable three and a half years at Mercedes working with an incredible team of people,” he said in statement. “I am now looking forward to a new challenge and wish everyone well at Mercedes.”

Lowe joined Mercedes from McLaren in 2013, just before the team went on to secure three-straight world championships.

Mercedes will operate in the meantime without a technical director. There are rumors that former Ferrari [NYSE:RACE] Technical Director James Allison may join the team.

Mercedes is also without a second driver for the 2017 season, though there are rumors that Williams driver Valtteri Bottas may be about to join the team.

In other F1 news, Renault on Wednesday announced that its Team Principal Frederic Vasseur is stepping down. Until a successor is found, the team will continue to be managed by current President Jerome Stoll and Managing Director Cyril Abiteboul.