£15m Anelka kicks off Chelsea's transfer window spending spree

What could be the most important move of Nicolas Anelka's career finally came to pass yesterday afternoon as he signed for Chelsea from Bolton in time to play in today's home Premier League match against Tottenham Hotspur.

The 29-year-old French international, for whom Bolton had rejected a £12.5m bid from Chelsea earlier this week, eventually moved for a fee of £15m, which was believed to include £2m worth of "performance-related" bonuses. The exact nature of those bonuses remains unclear, but Anelka – who will now earn £90,000 a week in what is believed to be a four-year contract – will clearly be hoping that his move to Stamford Bridge will enable him to earn the kind of medals he picked up as a teenage signing for Arsène Wenger's Arsenal.

Chelsea are due to follow up Anelka's arrival with the £10m signing next week of the Serbian defender Branislav Ivanovic from Lokomotiv Moscow. The 23-year-old is a versatile defender but is expected to become the club's first-choice right-back for the remainder of the season.

That may not be the end of Chelsea's spending. They have earmarked up to £50m for this January transfer window, with two other slots – a winger and creative midfielder – also identified to be filled, having also toyed with the idea of renewing their interest in Seville's Daniel Alves and another Brazilian, Internazionale's Maicon.

The agent Pini Zahavi is also understood to be work-ing hard to persuade Chelsea to sign Valencia's David Villa, although, so far, they are balking at the asking price, which would be in excess of £30m. They have also considered a move for another Lokomotiv Moscow player, the midfielder Diniyar Bilyaletdinov, who would also cost around £10m.

Chelsea's manager Avram Grant maintained that Anelka, whose inconsistencies and unreliability in the past earned him the nickname "Le Sulk", could now look forward to the best years of his career. "He's a player who wants to finish his career at a good club and win some titles, which is important to us," said Grant, who insisted that the idea of signing Anelka had only occurred to him "a few weeks ago".

Chelsea's owner, Roman Abramovich, has made winning the Champions League the priority this season, but also wants a change of style, with more expansive football. Much is now expected of the fit-again Michael Ballack while Anelka's arrival could lead to a change in formation, with Chelsea able to play two strikers and possibly reverting to a midfield diamond.

The chances are that Anelka, however, will be a longer-term replacement for Didier Drogba, who has again reiterated his desire to leave this summer. The Ivorian, currently on African Nations Cup duty, has never fully settled at Chelsea and became even more unhappy after Jose Mourinho's departure. Should he leave it is likely that the club may move before the start of next season for Internazionale's Zlatan Ibrahimovic.

With Drogba absent at the African tournament, which has also claimed the services of Salomon Kalou, and with Andrei Shevchenko injured, Chelsea have looked in need of extra firepower as they face what could be the crucial part of their season hampered by injuries to other key players such as John Terry and Frank Lampard.

Drogba's thoughts on the new signing remain unclear, and he may have been given additional food for thought by Grant's ready admission that he is having "second thoughts" about the merits of having so many African players in his squad, given that the African Nations Cup requires players to miss nine or 10 matches in mid-season. "Maybe you need to think if you are signing four players, or just two," Grant said.

The £85m man: How Anelka eclipsed Veron in the transfer stakes

By Glenn Moore

So, Nicolas Anelka replaces Juan Sebastian Veron as the most expensive player in football history. There is a certain symmetry for the two have much in common. Both are richly talented players who, too often, have failed to fulfil their potential.

Anelka has won the Champions League, with Real Madrid, and titles in England and Turkey. Veron, who was named in the list of 125 players chosen by Pele to mark Fifa's centenary, has won titles in Argentina, England (albeit as a peripheral figure at Old Trafford) and Italy.

Yet their regular moves, plus loans, testify to their struggles to settle. Managers buy the talent, then become frustrated with the player. The really great players, unless they have personal issues like Maradona, rarely move because clubs do not want to sell them. Zinedine Zidane played for three clubs, Pele and Franz Beckenbauer for two.

Veron played best when he was at the centre of the team, as at Lazio and Estudiantes. Anelka, oddly, has rarely seemer happier than at Bolton when he was the big fish. It seems even the most talented players need to feel wanted.

Nicolas Anelka's transfer fees: £85.8m

Paris St-Germain to Arsenal £500,000. Poached by Arsène Wenger as a 17-year-old

Arsenal to Real Madrid £22.3m. Won Champions League with Real, but still unhappy

Real Madrid to Paris SG £20m. Returned to his home city but soon loaned to Liverpool

Paris SG to Manchester City £13m. Anelka scored but Keegan's City still drifted

Manchester City to Fenerbahce £7m. Won the Turkish title but failed in Europe

Fenerbahce to Bolton £8m. Justified surprise move with steady stream of goals

Bolton to Chelsea £15m. The first piece in Avram's revolution? A replacement for Drogba or a partner? Possibly the last chance to do his huge talent justice

Juan Sebastian Veron's transfer fees: £76.2m

Estudiantes to Boca Juniors small fee. Lifted his father's club back into the top flight

Boca Juniors to Sampdoria £3m. Brought to Europe by Sven Goran Eriksson

Sampdoria to Parma £13m. Won Coppa Italia as provincial side made bid for big time

Parma to Lazio £18.1m. Inspired Eriksson's team to Serie A title, but sold as club imploded

Lazio to Manchester United £28.1m. Overshadowed by Roy Keane and fails to settle

Manchester United to Chelsea £14m. Signed by Claudio Ranieri but unwanted by Jose Mourinho, he was loaned to Internazionale, winning Coppa Italia twice, then to Estudiantes with whom he inspired their first title in 23 years. Now a free agent.