Tbh, I wouldn't place him in our legends either, but not for those reasons.
Zidane was a legendary player, even if he's more of a Madrid legend than Juve.
Pirlo, on the other hand spent the best part of his career with Milan, but enjoyed himself more in our shirt and was instrumental to our return back to the top, as same as Vidal.
But, Vidal left us the same way Zidane did - for a wealthier team in hopes of winning the CL.