The 34-year-old’s current deal expires at the end of the season, while it is Chelsea policy that players over the age of 30 are only offered 12-month deals.
“What I can guarantee is he will be a Chelsea player next season. I can guarantee that,” said Mourinho. “No doubts he’s going to get his contract.”
Mourinho has hinted he will rotate his team for tonight’s clash at West Ham following Sunday’s Capital One Cup final success, which handed the Portuguese the first trophy of his second spell in the west London dugout.
That may mean a recall for keeper Thibaut Courtois, who has usurped Wembley hero Petr Cech in the goalkeeping pecking order this term, although Mourinho insists any club eyeing a summer move for the Czech stopper will need deep pockets. He added: “If he tells me he wants to leave, I will tell him my opinion and my opinion is one of the three best goalkeepers in the world. Huge money.”