Kurt Zouma says Chelsea's FA Cup win over Peterborough shows Antonio Conte has the squad strength to challenge for the double.
The Premier League leaders made nine changes from the side which saw a 13-match winning run in the league end at Tottenham before beating Posh 4-1, the League One side managed by former Northern Ireland midfielder Grant McCann.
"It was really good for everybody who played, to show that we are still here and want to play also," Zouma said.
"We have a very good squad - that's why the manager can make changes. Everybody is doing a great job."
Asked if Chelsea can win the FA Cup in Conte's first season in charge, Zouma added: "I hope (so). We have the team to do it. We want to win this cup. It's one of our targets."
Conte is seeking reinforcements in the January transfer window, but will settle for his current squad if the right move cannot be made.
Zouma's comeback is a timely one. The defender was making his first-team return following 11 months out with a serious knee injury.
The availability of the 22-year-old France defender, plus the return of Nathan Ake from his loan spell at Bournemouth, has led Conte to say he is not looking for a central defender in the winter transfer window. "I'm ready to compete with the others," Zouma said.
Zouma is already looking ahead to the weekend's Premier League clash at champions Leicester, when John Terry is set to be suspended.
Terry could yet be reprieved. The 36-year-old, sent off for a last-man challenge on Lee Angol, said that he would be appealing against the decision to the Football Association.
"Amazing feeling, back at the Bridge, playing with the lads," Zouma said.
"We're a bit disappointed with the red card for the captain, but we got the win and I played 90 minutes, had no problems, so I'm very proud and happy.
"I was ready to play 90 minutes. I wanted to stay for the full game.
"We won the game, so now let's think about the next game."