Chelsea announced today, Friday, that they have signed Portuguese midfielder Renato Vega from Swiss club Basel on a seven-year contract with an option for an additional year. The two clubs did not disclose the transfer fee, but British media reported that Chelsea, under coach Enzo Maresca, paid around 14 million euros (15.26 million dollars) for the 20-year-old player's services. Chelsea finished last season in sixth place in the Premier League.