The Blues head into the game looking to return to winning ways after the disappointment of their 2-1 loss to Paris Saint-Germain in the Champions League in midweek.
City, meanwhile, will also be desperate to secure a victory after Manuel Pellegrini’s men suffered back to back Premier League home defeats by Leicester City and Tottenham in recent weeks.
However, with Chelsea having shown some signs of improvement under interim boss Guus Hiddink in recent weeks, former Everton man Gray is backing the Blues to beat the Citizens at Stamford Bridge on Sunday.
Writing in his blog for Paddy Power, Gray said: “Chelsea are warm favourites to win this one. It’s all they have to play for this season.
“Man City have a massive European campaign to look forward to, and a league to chase down. What’ll happen here that Chelsea will field a much stronger side than Man City.
“Manuel Pellegrini has to let one of the trophies go in order to keep pace, and it’ll have to be this one.
“They’ve got a final, a winnable European tie and an outside chance at the Premier League. He’ll rest a couple of big players and Guus Hiddink will capitalise.”
Chelsea’s next Premier League game is a trip to Southampton on Saturday 27 February.
Fourth-placed Manchester City, meanwhile, take on Liverpool in the League Cup final at Wembley later this month.
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news