Arsenal and England forward Theo Walcott is set to miss the FIFA World Cup after rupturing the anterior cruciate ligament in his left knee.
The 24-year-old suffered the injury in Arsenal's FA Cup third-round victory over rivals Tottenham on Saturday.
Although Walcott appeared in good spirits as he was taken from the field on a stretcher, signalling the 2-0 scoreline to Tottenham fans, he is now facing surgery and a lengthy lay-off.
A statement from Arsenal read: "After coming off injured in Saturday's 2-0 win against Tottenham Hotspur, the Club regrettably announces that Theo Walcott has sustained a ruptured anterior cruciate ligament of his left knee.
"Theo will have surgery in London in the near future and is expected to be out for at least six months, therefore missing the remainder of the season and the World Cup in Brazil in the summer.
"Everyone at Arsenal wishes Theo a speedy recovery and we look forward to seeing him back on a football pitch as soon as possible."
The Football Association confirmed earlier on Monday that Walcott would face no action for his gesture towards Tottenham's supporters.
Prior to his injury setback, Walcott would have been strongly fancied to gain a place in Roy Hodgson's England squad for the tournament in Brazil.
Despite making his international debut in May 2006 and earning 36 caps to date, the former Southampton man has yet to feature at a World Cup.
He was selected in Sven-Goran Eriksson's 23-man group for the 2006 showpiece, but did not make it onto the field, before being controversially omitted by Fabio Capello in 2010.
As well as representing a blow to England, Walcott's injury comes as a major blow to the Premier League title hopes of Arsenal, who are currently one point clear at the top of the table.
Arsenal manager Arsene Wenger has already conceded he is light on attacking options and will now have to cope without a player who had contributed five goals in his last five league starts.
Walcott enjoyed his most prolific season to date in 2012-13, finishing as Arsenal’s top scorer with 21 goals in all competitions.
|Sporting Lisbon 2 Roma 0: Slimani, Mane inspire Portuguese hosts|
|Rodgers feeling ready for new campaign|
|Khedira to miss Supercoppa|
|Paris Saint-Germain 2 Lyon 0: Aurier and Cavani seal more silverware|
|Wolfsburg 1 Bayern Munich 1 (5-4 on penalties): Super-sub Bendtner nicks it for Pokal champions|
|Lampard´s long-awaited New York City debut ends in defeat|
|Casillas the spot-kick hero for Porto|
|Monk bullish ahead of season opener at champions|
|Marseille 2-0 Juventus: Night to forget for Serie A champions|
|Swansea end pre-season with yet another draw|
|HJK 0 Liverpool 2: Origi and Coutinho on target|
|Juventus rocked by Khedira injury scare|
|Lens and Pantilimon star as Sunderland beat Hannover|
|Pardew hopeful of concluding Wickham deal|
|Martinez allays Lukaku fears|
|Stuttgart 4 Manchester City 2: Cause for concern for Pellegrini|
|Wasteful Bournemouth held by Hoffenheim|
|Jerome seals Norwich win|
|Souare´s first goal ensures Palace draw|
|Sinclair hits hat-trick in Villa draw|
|Leicester end pre-season with thrilling Birmingham win|
|Wood and Mowatt condemn Everton to friendly defeat|
|Coloccini not involved as Newcastle lose to Gladbach|
|Borussia Dortmund 2 Real Betis 0: Ramos scores on return from injury|
|Stoke lose to Cologne on Afellay debut|
|Norwich capture goalkeeper Kean|
|Jovetic hits out at Pellegrini following City exit|
|Jones backing new boys to spark United revival|
|Scottish Premiership Review: Celtic up and running, Dundee hammer Kilmarnock|
|Can keen to learn from Milner|
|Immobile on the mend following friendly scare|
|Sagan Tosu 1 Atletico Madrid 1 (1-4 on penalties): Simeone´s men need spot-kicks|
|Cahill: Big-spending rivals will make title race tougher|
|Roberto happy to play full-back for Barca|
|Gestede eager to make his mark at Villa|
|I want to play more and score more - Remy|
|Lambert influence important, says Pulis|
|Benteke a ´bargain´ buy - Rodgers|
|Zola: Qatar would be ideal for Balotelli, Cassano|
|Suarez: I´m not among world´s best|
|PSG ready despite ´chaotic´ pre-season - Blanc|
|Arsenal thumping still hurts - Fournier|
|Aubameyang targets Champions League success|
|Rooney set for Everton return|
|Cech can match Van der Sar - Wenger|
|Mourinho ponders Wenger´s losing record against him|
|CBF confirm Fred failed a doping test|
|Bournemouth beaten by battling Cardiff|
|Immobile injury overshadows Sevilla win at Vicarage Road|
|Lambert at the double on West Brom bow|
|Real sign up Spain starlet Vallejo|
|Valencia blow for West Ham|
|Elche cleared to play in Segunda Division|
|Baker pens a new Villa deal|
|Lambert makes Albion switch|
|Gillingham and Scally found guilty of ´race victimisation´|
|Inter complete Jovetic signing|
|Arsenal v Chelsea: Mourinho cools Wenger rivalry ahead of Wembley meeting|
|Villa snap up Gestede|
|Villa land Veretout|
|Mourinho coy on fresh Stones bid|
|Aubameyang commits to Dortmund|
|Torres on the hunt for trophies with Atletico|
|Cazorla and Walcott sign new Arsenal deals|
|Quick start vital in Arsenal title bid - Wilshere|
|I have received no offers - Guardiola|
|Barcelona to monitor Turan injury|
|Zorc ´surprised´ by Grosskreutz-Tuchel row|
|Phil Neville could be England manager - Moyes|
|UEFA to investigate Shakhtar´s Fred selection|
|City loan Unal to Genk|
|China v South Korea: Stielike looking for new options|
|North Korea v Japan: Halilhodzic to unearth new faces|
|Drogba: I want to be ready, not a burden|
|Hamstrung Clasie in doubt for Southampton league opener|
|West Ham goalscorer Zarate bemoans Astra comeback|
|Negredo quashes Valencia exit rumours|
|´This is not my Sampdoria´ - president Ferrero|
|Criscito could join Inter - agent|
|CBF endorse Zico´s FIFA presidency campaign|
|Hawit to handle CONCACAF´s referee review|
|Falcao is a ´top, top player´ - Terry|
|Tuchel pleased by Dortmund fighting qualities|
|Premier League rules out schedule changes for Champions League clubs|
|UEFA Europa League Review: Southampton stroll as Sampdoria are humiliated|