Michael Schumacher's departure from a Ferrari race seat in 2006 left the team "rudderless", according to Rob Smedley as the Scuderia still struggle to recapture the dominant glory days of Schumacher's run of title glory at the turn of the millennium.
Schumacher and Ferrari won five titles on the spin between 2000 and 2004 – the Scuderia having also secured the 1999 constructors' championship to build a Formula 1 record run of consecutive team trophies.
Fernando Alonso and Renault broke the sequence in 2005 and 2006, although Ferrari did return to winning ways with Kimi Raikkonen in 2007 and a 16th constructors' crown the following year, but that remains their last title.
Smedley worked at Ferrari as a test engineer and Felipe Massa's race engineer during Schumacher's spell in red and spelled out exactly how much of an impact his first retirement had.
Asked if the German great's departure affected Ferrari, Smedley said: "Totally. He was still involved in the team and there was thoughts at some point as to how involved he was going to be - he never wanted to do that and I think that was a shrewd move by Michael.
"But he still had involvement in the team. It's always never going to be the same when he's not driving, when he's not giving you that day to day in testing and racing, that feedback of where we are, what needs improving, the areas we need to work and 'don't worry about that and worry about this instead'.
"So the dynamic completely changed and it's fair to say we all probably became a little bit rudderless without him."
Smedley explained that Schumacher's personal approach behind the scenes was just as crucial to Ferrari's dominance as his efforts on the track.
He added: "My time at Ferrari that crossed with Michael, I was on the other car, so often we wouldn't see him until two days after the race.
"But he might've been at a race and completely dominated it and the first thing he did was come to the test team and go around every engineer, shake their hand and thank them and talk about stuff we'd done at the test.
"He was just a great guy to work with and I think once you've got leadership with people like that, it was kind of like the dream there between him Jean [Todt] and Ross [Brawn] and it was never going to fail to be honest. It was just so good."