The London Evening Standard says at just 33 years old, he is the same age as Chelsea players Frank Lampard and Didier Drogba and although his career has shown considerable promise, his appointment must represent something of a gamble by Roman Abramovich.
Villas-Boas's transition would be smoothed by a reported move for Porto's principal striker Falcao.
Arsenal and Tottenham were among several clubs monitoring the 25-year-old striker, who scored the winning goal in the Europa League Final and set a new record of 17 goals from 14 games during the competition.
Chelsea have indicated they are willing to pay around £25m for the player, who last month hinted he could leave the club. "At Porto, many players, and even the manager have clubs interested in them," said the Colombia international. "Porto is the most selling club in the world."