Striker Salomon Kalou signed a three-year deal on Monday and Alex followed suit on Tuesday by agreeing to a new four-year contract.
The Brazilian has been out of action since the start of the season following a groin operation but he resumed full training this week and had no hesitation in pledging his future to the club for a further four years.
Salomon Kalou set to sign new Chelsea deal
Ancelotti savouring English football
Football Rich List: QPR's Mittal tops latest figures
John Terry haunted by Ronaldo’s wink
Drogba: Chelsea should sign Patrick Vieira
Sport on television
“I am very happy to start again to train and feel no pain, and to sign for four more years,” said Alex.
“It was easy to decide to sign and now I hope to get back to playing well. My condition now is so-so. I think in two more weeks I am 100 per cent and can play without a problem.”
But with Brazil, under coach Dunga, having qualified for the World Cup finals in South Africa next summer, Alex is determined to force his way into Carlo Ancelotti’s team.
“I hope now to start to play in the Chelsea games and play very well. He [Dunga] has spoken to me and said: ‘I am happy to see you playing again. I hope you start to play well and I will call you to play in the national team again’.
“To go back into the national team is important to me. Also the Chelsea team started very well this season, is at the top, and this season to win the Premier League is important to me. Now I want to play.”
Ancelotti has yet to manage Alex in a Chelsea game but is well-versed in the Brazilian’s ability.
His AC Milan side contested a tight Champions League semi-final in 2005 when Alex was at the heart of the PSV Eindhoven defence.
Ancelotti welcomed the defender’s decision to continue his career at Stamford Bridge and told the club’s official website: “I am very happy that Alex has signed a new contract with the club. He is just returning from injury and surgery but he is a player I know well.
“I am familiar with all of his fantastic qualities, so I am delighted he will be with us for another four years.”
Chelsea are determined to tie up as many of their stars on fresh deals following FIFA’s transfer ban.
The Blues are prevented from signing any players in the next two transfer windows after being found guilty of inducing teenager Gael Kakuta to breach his contract with Lens two years ago.
Chelsea have appealed against the verdict and are hopeful of getting it overturned but in the meantime they are determined to keep their current squad together.
Kalou, 24, and Alex have joined John Terry, Ashley Cole, Didier Drogba and Michael Mancienne in committing their long-term futures to the club.
There had been some rumoured cross-capital interest in Kalou from rivals Arsenal, but the Ivorian was pleased his future had been settled.
Kalou also helped Ivory Coast reach next summer’s World Cup in South Africa over the weekend, and the new contract caps a fine week for him personally.
“I am delighted to stay here for the next three years so I can improve my game and play more games,” said Kalou.
Meanwhile Portugal midfielder Deco is hoping he can rekindle his early-season form after returning to the Chelsea side against Liverpool.
Deco, given a new lease of life under new coach Carlo Ancelotti, was in fine form until a calf injury left him struggling on the sidelines.
But the Chelsea playmaker is hoping that his return to action will help him rediscover his early-season success when he was played behind the main striker in Ancelotti's 'Christmas tree' and 'diamond' formations.
"I was happy and I hope to start again now playing how I was earlier this season," said Deco.
"I like the system we are playing – it is different to last season but I have played it before."