Capped 48 times by Brazil, Adriano has been plagued by off-field problems throughout his career and after leaving Inter he had a brief successful spell with Flamengo before an ill-fated move to AS Roma.
After having a four-year contract with Roma cancelled after just seven months in 2011, Adriano struggled to resurrect his career in Brazil. Miami United are one of several lower league clubs in South Florida.
Adriano's former Brazil team mate Ronaldo is co-owner of Fort Lauderdale Strikers in the second division North American Soccer League (NASL) and they have numerous Brazilian players.
Former AC Milan captain Paolo Maldini is joint owner of a new Miami FC club in the NASL which is coached by ex-Milan and Lazio defender Alessandro Nesta.
David Beckham, the former England and Manchester United midfielder, has been working to bring a top-flight Major League Soccer team to Miami.
(Reporting by Simon Evans in Miami, editing by Ed Osmond)
