Eddie Newton has revealed the call to help save Chelsea's season came "totally out of the blue".
The Blues announced this afternoon that their former midfielder had joined caretaker manager Roberto Di Matteo's backroom staff until the end of the campaign following the sacking yesterday of Andre Villas-Boas.
Newton told Sky Sports News: "It was totally out of the blue. It's been a blur to be honest with you.
"The ambition is to get into fourth place and we will push as hard as possible.
"Every game is very important between now and the end of the season."
He added: "I can't talk about what has been done before, but I am Chelsea through and through and we want that drive and that will to win, and when we get that, it becomes a habit again."
Newton, 40, spent almost a decade at Stamford Bridge and he and Di Matteo scored the goals that won the club the 1997 FA Cup.
He was also part of the League Cup and European Cup Winners' Cup sides the following year and, after his playing career was ended prematurely due to injury, he returned to Chelsea with a role in the academy.
He went on to become assistant manager under Di Matteo at both MK Dons and West Brom, leaving the Baggies when both were sacked last January.
Chelsea also confirmed that fitness coach Jose Mario Rocha and chief opposition scout Daniel Sousa had left the club, the pair having been part of Villas-Boas' coaching team.
Steve Holland keeps his job as assistant first-team coach and Christophe Lollichon remains as goalkeeping coach, while Chris Jones has stepped up to the role of first-team fitness coach.
Di Matteo and Newton's first task will be to navigate tomorrow night's FA Cup fifth-round replay at Birmingham.
The build-up to the game continued to be completely overshadowed today by the fallout from Villas-Boas' sacking, with Chelsea branded a "serious embarrassment" and managing them described as "hell".
Roman Abramovich is searching for his eighth manager after Villas-Boas was given his marching orders yesterday, only eight months since his appointment.
The Portuguese's downfall was strikingly similar to that of Luiz Felipe Scolari, who also lost his job amid reports of a player revolt three years ago.
Pep Guardiola and Jose Mourinho are said to be top of Abramovich's managerial wishlist, but Scolari had a stark warning for the man who ultimately replaces Villas-Boas.
"It will be hell for whoever succeeds him," he told a news conference in Brazil, where he now manages Palmeiras.
He added: "This move is strange - although it's not so strange to me because of what I went through there.
"Some things are known, like the relations with the owner, who has the relationship with some players before the coach.
"Villas-Boas was a champion and he will continue to be.
"He needed to replace at least seven or eight players, even since I was there, but he failed."
League Managers' Association chief executive Richard Bevan was scathing about Chelsea's latest decision to dispense with a manager.
"What's for sure is the club, despite unlimited wealth, haven't yet worked out how to build a successful football club," Bevan told Radio Five Live.
"Looking for what is an eighth manager in nine years is a serious embarrassment to the owner, the club, the fans and the league."
Di Matteo was yesterday put in charge until the end of the season, although there have long been suggestions he is even less popular than Villas-Boas.
Bevan revealed how the Portuguese reacted to his sacking, which came after training yesterday, with the news delivered in person by Abramovich.
"He was very disappointed, frustrated, saddened, but his thoughts were for the club, the fans and indeed Roberto Di Matteo, wishing him well for the rest of the season," Bevan said.
Bevan claimed the frequent managerial changes at Stamford Bridge did not help Villas-Boas develop a relationship with his players.
"Players need to know that the manager's strategy and his job is not in question; there's a clear remit," he said.
"You get success if you get time, and stability will come from that. Otherwise it's very difficult for a manager like Andre to impose his philosophy and build a team."
Villas-Boas' side had won just three times in 12 league games and he had the lowest win percentage of any Chelsea manager since Glenn Hoddle.
Bevan added: "After only eight months, you can't build that sort of success. The club's still competing in the latter stages of the Champions League, the FA Cup and fighting for a top-four position.
"If you want success, you must look at the longer term."