Arsenal completed the signing of highly-rated Porto midfielder Fabio Vieira in a 40-million-euro ($42 million) deal on Tuesday. The 22-year-old has emerged as one of Europe's most gifted young stars after coming through the Portuguese club's youth system. He played a key role in Porto's domestic double last season, scoring seven goals and providing 16 assists in all competitions. Praising Arsenal's third signing of the transfer window, Gunners manager Mikel Arteta said: "I am very excited that we have identified and signed such a special talent.