Jose Mourinho says captain John Terry will receive a contract extension at Chelsea and believes the defender has the desire to ensure next season will not be his last at Stamford Bridge.
The 34-year-old's current deal expires at the end of the 2014-15 campaign, but Mourinho believes his form means he will be staying at Stamford Bridge.
"What I can guarantee is he will be a Chelsea player next season. I can guarantee that," Mourinho said.
"No doubts he's going to get his contract. I know what my board tells me. I also know what the player tells me."
Chelsea policy dictates that players over the age of 30 are offered only 12-month deals, a challenge Terry has taken in his stride, according to Mourinho.
"I don't know (how long he can play on for). At this age it's very difficult to predict," Mourinho said.
"At Chelsea, we decided at a certain age - to stimulate the players, to provoke the players, to make them feel the past doesn't play a role and it's all about the present and tomorrow - they get one year of contract.
"If they don't accept they are not ready for the challenge, and we wouldn't want them. John accepted the first challenge last year, accepted this season already. That is a guarantee the fire is there.
"If the fire is there, this contract will not be the last contract he signs."
Terry signed his current deal 48 hours after the end of last season - Mourinho's first back at Stamford Bridge - but his next offer could come soon.
"It will be before the end of the season, for sure," Mourinho said.
Asked if terms had been agreed, but the deal not yet signed, the Blues boss said: "I think it's around that."
Mourinho also believes he has time to find Terry's successor in the centre of the Blues defence - Kurt Zouma could prove to be that man - after helping to revive a career which appeared to be on the downturn under the Portuguese's predecessor Rafael Benitez.
"This is a process we can take our time, because John is proving again this season that he's a player for years," Mourinho added.
"When I came back (in June 2013) he was coming from a difficult period. Last season he was very good, this season I think even better."
Terry lifted the Capital One Cup on Sunday following a 2-0 win against Tottenham at Wembley. He now has 13 major trophies for the Blues.
It was Mourinho's first trophy of his second spell.
Petr Cech played in goal at Wembley, despite being displaced as first choice by Thibaut Courtois this term.
Mourinho will not stand in Cech's way should he wish to leave at the end of the season, b ut the Czech Republic goalkeeper's status means a big fee will be required to prise him from Stamford Bridge as his contract does not expire until the end of next season.
"He will make his decision," Mourinho said.
"I would like him very much to stay (but) I don't waste my time trying to persuade him, because I know nobody can persuade him.
"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."
Cech will be a substitute at West Ham on Wednesday, with Courtois back in the side after missing out at Wembley.
"I didn't explain it. I just decided," said Mourinho of his goalkeeping choice for Wembley.
"I didn't need to speak with him (Courtois) to understand he was sad, but I think that (at West Ham) Petr will be sad because Courtois is playing."
Mourinho followed his first trophy in English football, the 2005 League Cup, with Chelsea's first championship in 50 years.
Chelsea resume their bid for a first Premier League title in five years at Upton Park, five points clear with a game in hand after second-placed Manchester City lost at Liverpool on Sunday.
Mourinho thinks the title is about more than just two sides.
"Arsenal nine points (behind), Manchester United 10 points," he said.
"Mathematically it is open, and not just mathematically. 12 matches is a lot."
West Ham have one win in 10 Premier League games - a run which includes a 2-0 loss at Stamford Bridge - but Mourinho is taking nothing for granted and knows it is important to win after Sunday's double boost.
He added: "It's a massive match, a very difficult match.
"We are going to West Ham and to teams who desperately need points: Leicester, Hull, QPR, West Brom, Arsenal, fighting for top four.
"West Ham don't need the points. I don't think they are going to play Champions League, but they are not going to have relegation problems.
"They have nothing to lose. They will play to try and win the game."