The Moroccan is believed to be a long-term target of Blues manager Roberto Di Matteo, who is keen to bolster his defensive options for the club’s Premier League challenge.
But, they face real competition for his signature as Juventus have reportedly upped their interest in the centre-back ahead of a possible January swoop.
Despite him having signed a new contract last summer which runs until 2017, the Turin club are confident that a £10m swoop may be enough to tempt their Serie A rivals to part company with the 25-year-old.
Udinese have a number of targets lined up for the inter transfer window and the funds they could gain from any potential deal may force a quick sale.
Barcelona are also believe to be monitoring the situation, with issues regarding the fitness of Carles Puyol and Gerard Pique worrying manager Tito Vilanova.
Benatia is regarded as top target by the Blues with some member of the team’s hierarchy unconvinced by the recent performances of a number of the squad’s defensive players.
With Udinese employing a three-man back line, Di Matteo could be tempted to bring in the centre-back to boost his tactical options both in the Premier League and Europe.