After nearly two years out of management, Benitez was brought in Wednesday to replace the fired Roberto Di Matteo with Chelsea's league challenge faltering and a successful defence of its Champions League title looking unlikely.
A lot has changed since Benitez last worked in the Premier League — the final game of his six-year stint at Liverpool was in May 2010 — and that includes the emergence of big-spending City as a force.
After winning the title last season, City has climbed back to the top of the standings and is four points ahead of third-place Chelsea going into the match at Stamford Bridge.
Manchester United, which was toppled by City after a surprise 1-0 loss at Norwich on Saturday, hosts last-place Queens Park Rangers. A home victory could be the final straw for under-fire QPR manager Mark Hughes — a former United player.
City's first loss of last season came at Chelsea, and if the European champions can repeat those exploits 11 months ago, Benitez would go a long way to convincing those supporters who doubt whether his hiring until the end of the season is an upgrade from Di Matteo.
"Rafa Benitez is a great coach," Chelsea playmaker Juan Mata said. "He's got lots of experience and won a lot of trophies with Liverpool, taking them to a very high level. He knows the Premier League, too."
Benitez's first dilemma is whether to recall misfiring striker Fernando Torres, who was dropped by Di Matteo for the 3-0 loss at Juventus in the Champions League on Tuesday. Benitez and Torres enjoyed a strong working relationship at Liverpool, with the striker arguably producing the best form of his career.
Benitez also has to shore up a leaky defence that is still missing injured captain John Terry, at a time when City's attack seems to have clicked.
The defending champions thrashed Aston Villa 5-0 last weekend and created enough chances late in the 1-1 draw against Real Madrid on Wednesday to have scraped a win that would have kept its qualification hopes alive. Argentina striker Sergio Aguero has scored in each of his past four matches after a low-key start to the campaign, while Carlos Tevez has netted six times already in the league, looking a different player to the one that spent most of last season on strike.
"A very important factor is the fact I have all my family here in Manchester, which makes me very happy," Tevez said. "I am not worrying about the things I used to worry about, I am just concentrating on enjoying my time out on the field."
Hughes was expected to become the first Premier League manager to be fired after his team's winless start was extended last weekend with a dispiriting 3-1 home loss to Southampton.
QPR owner Tony Fernandes has held fire for the moment but a heavy defeat at United could make Hughes' position untenable. The west London club is five points from safety, having only picked up four points so far.
United will also be desperate to avenge its sloppy loss at Norwich, with its best players fresh after being rested for the Champions League match at Turkish side Galatarasaray on Tuesday.
Also Saturday, fourth-place West Bromwich will look to maintain its surprise start to the campaign when it travels to Sunderland and fifth-place Everton hosts Norwich. The other games are: Stoke vs. Fulham, Wigan vs. Reading and Aston Villa vs. Arsenal.
On Sunday, Liverpool manager Brendan Rodgers makes his first return to Swansea since leaving the Welsh club for Anfield in the off-season. Southampton hosts Newcastle and Tottenham is at home to West Ham.