|Official Messi Signed Merchandise. This F5 Adidas boot was personally signed by Lionel 'Leo' Messi in an exclusive signing session organised and carried out in Barcelona on 26 September 2014. At just 27, Leo Messi has already scored over 400 career goals, 91 of which he scored in just one calendar year. There is no doubting that Messi will go down as one of the all time footballing greats. Celebrate Messi's incredible career with this specially signed Adidas F5 boot. All Official Messi Signed Merchandise is created under license and comes with an Official Messi Signed Merchandise Certificate of Authenticity, which has an image of Leo signing the product..